Very strange behavior in Panel - can't delete text in fields

My Kirby sites (testet with 2) hosted at One.com suddenly show a very Strange behavior. No issues in the past and still everything fine on localhost.
If I add text to a textfield somewhere in the panel and save, everythng ist fine. If I delete some text in the field and save, nothing changes… the old string is there. So I can add but not delete text.

Looks to me like they changed stuff in the php config but they say, they didn’t.
Here is the PHP Info http://www.eduardwarkentin.de/info.php

Could it be a problem with OPcache?

Hm, weird. Can you disable Opcache?

the only thing I can change there is the PHP Version.

Have you tried that?

Yes, but you can just choose between 7.2, 7.3 and 7.4 (beta)

Then try 7.2, or do you mean you have already tried that to no avail?

After all, if you really haven’t changed anything and it’s likely they have. And if they did, they have to support you to make it work again.

Does it work if you disable the browser cache? Have you tried with different browsers?

I tried PHP 7.1 and 7.2 and 7.3. Cleared the browser cache and tried an other Browser. No effect.

Can you see any errors in your log files or console?

No visible error in browser console or browser. I don’t know how to access PHP log files

Strange thing is that we have another issue only today with one.com: Can't log in to panel

Maybe you can talk to their support again, mentioning you are not the only one who suddenly has issues you didn’t have before.

The cause of the issue was a missing module after the hosting company changed something in their setup.