I'm pretty sure that the problem is related to this enhancement in 131.0-Beta2 https://github.com/unacms/una/issues/4389

My production server runs on version 13.0.0-RC4 and doesn't have those problems. It seems that the replacement of those placeholders has issues. Sometimes it works, sometimes it doesn't.

@LeonidS is going to check it on my test server, as he told me.