Wait - you are saying you have two IPs on one interface? ex. two different IPs in two different /30’s at the same time on one interface and OSPF neighbor with both?
If so, I think that is a bad idea, and it may be responsible for your instability. Whenever I have a single interface going to multiple routers, I create VLANs on that interface, then the VLAN gets the IP. OSPF sometimes behaves a bit strangely when you have more than one IP on an interface that you are trying to form a neighbor relationship over.
I have many IPs on that interface. Multiple of them are doing OSPF. A couple are not.
Keep in mind the issue with one router is every 1-3 days. The other router is after maybe a week or two. The first router has 0 problems talking to a Powercode BMU in the same situation - it only happens when I move it back to a Mikrotik (CCR).
Yes I understand, but the way you have things set up is very uncommon, and so you are highly likely to run into some corner case bugs than if your setup was more typical. It also makes it harder to manage your OSPF interfaces because they are all tied together. I would strongly advise moving to a VLAN-based design rather than having multiple IPs on the same interface, at least for links that you are forming OSPF neighbor relationships over.
I know Cisco routers do not allow you to form OSPF adjacency on a secondary IP address, so if you had Cisco your current setup would not be possible (that in itself should demonstrate how unusual this setup is). MikroTik may allow you to configure this, but I do not know if it will work correctly. You could run into issues with DR/BDR reachability that would cause routes to disappear, which seems to be what you are actually experiencing.
Hopefully it’s acceptable to update to this thread. I’m still having issues.
This morning I created a vlan 118 interface on the router with multiple IPs and then on the new tower router I did the same. I did a /30 between them (on this vlan 118).
It worked right away up until about 9 hours later, at which point the same problem came back - the remote router would only have routes in OSPF from itself.