Version 13.0 reboots intermittently

[Christos Chatzaras]

> On 17 Apr 2021, at 16:14, Software Info <softwareinfojam at gmail.com> wrote:
> 
> Hi All,
> I had 12.2 working without issue as a VPN Server running OpenVPN. I
> upgraded to version 13.0 last night and now the server intermittently
> reboots. I saw a core.tt file which I have attached. I would
> appreciate any help I can get.
> 

This looks similar:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254309

Does this help?

sysctl net.inet.tcp.sack.enable=0