@jameswebb:
Can you try disabling TLS-Auth - then we can try and pick out the problem further if this works.
James
Alright.
So I disabled TLS-auth for the remote OpenVPN. And rebooted a few times, to test.
After each reboot, I can connect from my client w/o problems (deleted the tls auth in the config).
BUT it seems OpenVPN server 2 (p2p) got somehow affects as now the pfsense cannot tracert nor ping the branch office pfsense (not even the tunnel IP) but the branch office pfsense can successfully ping the headquarter pfsense. (that worked before, I even tested a anything-open-for-anything rule for LAN just in case)
After that I enabled TLS-auth again, with the original key. My client was still able to connect successfully.
After that I rebooted once again and it remains working. So the bug seems to be fixed, which is great.
The pfsense can still not ping the branch office pfsense (yes the BOpfsense has a rule on OpenVPN to allow anything for the HQpfsense and as written it was working before). I'd like to get that working again, too. But as long as both OpenVPN are working again without flaw also after reboots I'm quite happy again.
Thanks for the hint.