Tried on some of your images, they are displayed fine when clicking a thumbnail, no problem. But Firefox Inspector also says "Uncaught SyntaxError: missing ] after element list" and that is the
RVAS = {
derivatives: [
...
list at the bottom. That's not Piwigo core code so some plugin.
The problem there is that "Warning: Undefined array key "path_ext"" messages are injected and break the list, you can see when looking at the generated page code in Inspector or after Ctrl+U.

Either disable displaying deprecated and warning messages (because as seen it effectively may break functionality of a page even if nothing else is broken), in local config

$conf['show_php_errors_on_frontend'] = false;

or fine tune message classes to display, see [Forum, post 183126 by erAck in topic 31852] Menubar tags issue after 12.2.0 upgrade, or better, log to file instead.
See [Forum, post 180778 by erAck in topic 31258] Error Message.