@jimp:
How many Phase 2 entries do you have?
IIRC AWS will only allow so many P2 entries (3, I think) and if you establish another one after that, they will disconnect one of the previous entries in exactly that fashion.
Hi,
I had since found the issue and that was in fact the problem. These symptoms are buried in this Amazon tech note https://aws.amazon.com/premiumsupport/knowledge-center/vpn-connection-instability/. Really difficult to track down because you don't have access to any logs on the AWS side…
Cheerio, Harry.