I'm inclined to agree with you - looking at OpenVPN PID files, quite a few of them had really high PID numbers, into the billions!
I can run;
killall openvpn ; rm -f /var/run/openvpn_*
Then when the services are restarted, they all work fine until the next service crash or config reload.
Also, (probably because of this issue), if I have the faulting services in Service Watchdog, I eventually end up having to reboot the routers (PID exhaustion? Is that still a thing these days?).
Anyhow, probably a week from today, I'll be able to get us a few dates that we'll be quiet enough to not suffer from having to reboot systems, etc.