We have S2S VPNs to many of our clients, ASA to ASA. A bunch of them have stopped working. The upgraded unit was on 9.9 code.
I don't see anything particularly suspicious in the release notes that would indicate any major changes to VPNs. I see some older crypto is being deprecated eventually but not yet.
Another thing which I already have a TAC case on is our remote vpn users can't establish Audio to each other. TAC is looking at that, but wondering if this is all related?
I may just downgrade tonight.