It is however with much enthusiasm that I am practicing scales and Hanon.
Curb your enthusiasm.

I watched your video. You have three main problems:

1. You are passing the thumb under. Have a look here for the alternative:
https://pianoforum.net/smf/index.php/topic,1918.msg15015.html#msg15015(Thumb under/over – detailed explanation – Fosberry flop)
https://pianoforum.net/smf/index.php/topic,3100.msg27113.html#msg27113(thumb over – hand displacement – practising with awareness – awareness is not thinking – learning by imitation)
https://pianoforum.net/smf/index.php/topic,7226.msg72166.html#msg72166(Thumb over is a misnomer: it consists of co-ordinating four separate movements).
2. In order to negotiate the smaller size of the thumb you are “twisting” your hand and “reaching” for the key with the thumb. Instead use your arm to position your thumb by moving it forwards.
3. You have a general misalignment of the joints (possibly caused by trying to play with your fingers, rather than using the whole playing apparatus to direct your fingers). I am afraid that Hanon tends to direct on into this sort of (bad) technique.
It is not really possible to tell you what to do. You must have someone demonstrate the correct movements (or watch a video where such movements are demonstrated).
In the meantime, read about it here:
https://pianoforum.net/smf/index.php/board,4/topic,4880.3.html#msg46319(discusses how to acquire technique and what technique actually is)
https://pianoforum.net/smf/index.php/topic,2024.msg16583.html#msg16583(how to aim the pinky – using the arm to move the fingers)
https://pianoforum.net/smf/index.php/topic,2033.msg16635.html#msg16635(finger strength)
https://pianoforum.net/smf/index.php/topic,2076.msg17157.html#msg17157(Speed – the 3 most important factors)
https://pianoforum.net/smf/index.php/topic,2079.msg17335.html#msg17335(Hand tension – not using fingers to play)
https://pianoforum.net/smf/index.php/topic,2359.msg20442.html#msg20442(Fingering placement on the keys)
https://pianoforum.net/smf/index.php/topic,2230.msg20686.html#msg20686(Octaves and fast octaves – excellent post by Robert Henry)
https://pianoforum.net/smf/index.php/topic,2477.msg21403.html#msg21403(Double thirds – the movement)
https://pianoforum.net/smf/index.php/topic,2502.msg21594.html#msg21594(Independence of the 3rd and 4thfinger – it is impossible, one should work towards the illusion of independence: it is all arm work)
https://pianoforum.net/smf/index.php/topic,2507.msg21688.html#msg21688(Round fingers – the role of fingers)
https://pianoforum.net/smf/index.php/topic,1808.msg23879.html#msg23879(Ultra fast arpeggios – slow practice x slow motion practice – good post by Herve – Abby whiteside is also mentioned)
https://pianoforum.net/smf/index.php/topic,2814.msg24872.html#msg24872(How a student’s physicality affects teaching – discussion on arm x fingers – moving from the centre: tantien and taichi – Seymour Fink gets discussed as well)
https://pianoforum.net/smf/index.php/topic,2809.msg25013.html#msg25013(Body movement – piano playing and martial arts)
https://pianoforum.net/smf/index.php/topic,2948.msg25927.html#msg25927(Czerny x Scarlatti to acquire technique – Ted gives an excellent contribution)
https://pianoforum.net/smf/index.php/topic,2973.msg25970.html#msg25970(How to create a cantabile effect – several approaches: creating a mental image, outlining, the three basic ways to bring out a melody)
https://pianoforum.net/smf/index.php/topic,3036.msg26638.html#msg26638(trills and melody in the same hand)
https://pianoforum.net/smf/index.php/topic,3530.msg31559.html#msg31559(how to bring out a melody – 3 different ways – Importance of a mental representation: hear in your mind and the fingers will comply)
https://pianoforum.net/smf/index.php/topic,3726.msg33453.html#msg33453(playing with curved fingers – worry less about movement and more about sound)
https://pianoforum.net/smf/index.php/topic,3987.msg36197.html#msg36197(etudes and alternatives to them)
https://pianoforum.net/smf/index.php/topic,4082.msg37362.html#msg37362(one cannot learn technique in a vacuum. At the same time one cannot simply play pieces – comparison with tennis)
https://pianoforum.net/smf/index.php/topic,4182.msg38775.html#msg38775(Hanon: pros and cons – Robert Henry’s opinion)
https://pianoforum.net/smf/index.php/topic,4164.msg39149.html#msg39149(CC Chang and relaxation for playing fast passages)
https://pianoforum.net/smf/index.php/topic,4282.msg39831.html#msg39831(How to increase speed: slowly using metronome x fast with chord attack – juggling and skiping rope as examples)
https://pianoforum.net/smf/index.php/topic,4144.msg40259.html#msg40259(improving speed of LH – move the whole LH not only fingers)
https://pianoforum.net/smf/index.php/topic,4385.msg41226.html#msg41226(technique is personal and relative to the piece – Fosberry flop – the best books on technique)
https://pianoforum.net/smf/index.php/topic,4734.msg44770.html#msg44770(how to acquire virtuoso technique – aiming at 100 pieces in five years)
https://pianoforum.net/smf/index.php/topic,4880.msg46339.html#msg46339(definition of technique: quote from Fink, Sandor and Pires – Example of the A-E-A arpeggio)
https://pianoforum.net/smf/index.php/topic,5034.msg47829.html#msg47829(The finger strength controversy – some excellent posts by xvimbi)
https://pianoforum.net/smf/index.php/topic,5352.msg50998.html#msg50998(Exercises x repertory – why technique cannot be isolated from music)
https://www.pianoforum.net/smf/index.php/topic,7887.msg79326.html#msg79326(why the lifting of the 4th finger is a non-problem)
https://www.pianoforum.net/smf/index.php/topic,7682.msg77042.html#msg77042(hand independence: how to create a cue system and what is hand memory).
https://www.pianoforum.net/smf/index.php/topic,8335.msg84684.html#msg84684(circular movements to avoid co-contraction)
https://www.pianoforum.net/smf/index.php/topic,8322.msg84686.html#msg84686(speed and muscle tension – 3 important components of speed playing)

I wish you good luck.

Best wishes,
Bernhard.