Bug in IPSec Phase 2 settings: upgrade loses settings

[rcfa]

There is one little, but consequential issue:

I have Phase 2 ESP encryption set to "AES auto"
but after the last two upgrades it each time was reset to "AES 256"

As a result, the tunnel doesn't come up properly after an upgrade, because the other side may have a different level, such as e.g. AES 128.

Upon further investigation, what also seems to happen is this: I select "AES auto", then I hit save, and the Phase 2 overview shows me "AES (auto)".
Then, when I hit the "Apply Changes" button it sometimes simply snaps back to "AES 256".

I'm somewhat baffled, because the behavior seemingly isn't really fully repeatable.