OpenVPN server restart causes permanent SSL CPU increase (RB4011iGS+ / RouterOS 7.13.4)

RouterOS
1

Dear Mikrotik community I have a problem:
Each time I take down and then up again the ovpn-server interface ssl takes 24% more resources: an entire new CPU core. The problem started 30m after issuing a new certificate for the server. Even during nighttime when nobody is connected the consumption does not drop. I can not switch off and on due to other services.

ssl ~24%(CPU) - off/on ovpn-server ->ssl ~50% - off/on ovpn-server -> ssl ~75%
Current situation

################
system resource cpu print

0 cpu0 100% 0% 0%
1 cpu1 100% 2% 0%
2 cpu2 5% 1% 0%
3 cpu3 100% 1% 0%
#################
tool profile
ssl 74.6%
################
RouterOS 7.13.4
user manager 7.13.4
architecture-name: arm
board-name: RB4011iGS+
platform: MikroTik

I thank you very much for your time, any info, idea, suggestion is appreciated.

2

There have been over 40 stable RouterOS releases since your version, with dozens of ovpn related changes and fixes:

MikroTik · Downloads

You should first try the latest stable or long-term version to see whether the problem is still reproducible or has been already fixed.

3

Sometimes restart helps a lot.
There always should be maintenance "time window" scheduled to be able to upgrade/reconfigure router.