ACME CLient HTTP challenge - Token not found

[PotatoCarl]

Hi
I configured some time ago the ACME client for an internal rocket.chat server. Which worked well, but it seems to be broken at some time in the last 60 days (update to 22?). That means, that the cerficate is not renewed anymore.
The message is "timeout while retrieving token".
My configuration is that I have 2 DSL lines with 2 routers, and the exposed host ends up on the OPNSense. The routers have both external IP4 addresses.
I use HTTP challenge.
It worked well for quite some time (like 2 years) and not suddenly stopped (which I only noticed when the certificate was outdated).
Is there any change in the configuration? Is there anything broken with the update to 22?
I am using 22.1.6 as version.
Please, any hints?
THank you.

[PotatoCarl]

As the token is checked for at port 80 (HTTP) it should not be an issue, however, just to notify, I am running VPN servers on port 443. THis however is also running for years...

[PotatoCarl]

Hi, HAs anybody this issue? Is there anyone who can help?
Due to my provider, I cannot use DNS challenge. TLS would be a problem, as I am running OpenVPN on these ports (cmopatibility with some hotel firewalls).

I can trace back the isse to the upgrade to 22.1.
The last time successfully the certificate was updated was Feb 6, on version 21.

Please help. Any suggestions are welcome.

[PotatoCarl]

Something happened and it works again. No idea what changed. Certainly I did not change anything.