@jimp
2.5.x dev builds.
I am in the exact same scenario - using 2.5.x to be able to run AES-GCM and it was working flawlessly for months and months until I updated around Christmas, and then it choked out 2-3 times since, prompting this post.
I switched to non-AES-NI on both IKEv2 setups and it is solid for 24hrs plus right now.
I will update both machines on Friday and re-instate the AES-NI ike v2 and see how it goes.
box 1:
2.5.0-DEVELOPMENT(amd64)
built on Fri Jan 03 22:01:28 EST 2020
box 2:
2.5.0-DEVELOPMENT(amd64)
built on Fri Jan 03 22:01:28 EST 2020