First of all, I would like to thank you for always taking the time to reply here.
It makes you feel not so alone with your problems.
Generally I always try to exclude that problems are due to our database contents or settings and thus I try to recreate this either in your demo system and/or in a local Xampp environment with a newly installed Tiki.
Also, I'm not sure if it's right to post these problems/questions here - at least hoping you're not the only one with these issues.
To get back to the problem. This also occurs with an empty database, i.e. a new installation without images in the database.
Therefore, it would have been nice to be able to reproduce it in your demo system with 21.5.
Does it make sense to report this as a bug - is there already the option to set up a 21.5 environment? - Maybe I will notice that it is not reproducible in the environment.