Solution:
Your <script type='text/javascript' src='https://mywebsiteurl.com/wp-includes/js/jquery/jquery.js?ver=3.5.1' loads not jQuery 3.5.1 because Google Chrome says:
...Either the 'unsafe-inline' keyword, a hash ('sha256-qqGbxWM7uia3gTh3zKaastub6jkpM0ypMYPp6TZvrLc='), ...'
The sha256-qqGbxWM7uia3gTh3zKaastub6jkpM0ypMYPp6TZvrLc= is not a hash of jQuery 3.5.1, whose real hash is 'sha256-QWo7LDvxbWT2tbbQ97B53yJnYU3WhH/C8ycbRAkjPDc='.
In case of jquery.min.js hash for v3.5.1 will be sha256-9/aliU8dGd2tb6OSsuzixeV4y/faTqgFtohetphbbj0=.
Check what you load really, in case of jQuery forks their right work is not guaranteed.
Original jQuery 3.5.1 supports nonce-value (proof).