GRE with IPSec problems - interface link down

Hi all!

I have this strange situation with one of my GRE with IPSec setups.

There are 3 sites, all connected and see each other over GRE with IPSec tunnels. The setup is basic with no additional “spices” straight from the Mikrotik manuals. Everything is working but sometimes tunnels go down with no obvious reason. In the logs you will wind just a message “GRE link down”. And it will not go automatically up unless you will disable and re-enable that interface. It can happen few times per 24h sometimes few times in 1h.

Does anyone have any similar experience?

P.S. now I disabled IPSec on these tunnels and already for 24h it’s running without any problems, so it suggests that there might be some bug with IPSec in RouterOS 6.40.2 ?

Thanks in advance!