Akka.Persistence: RecoveryTick dead letters

[Aaronontheweb]

Version Information
Version of Akka.NET? v1.5.27.1
Which Akka.NET Modules? Akka.Persistence

Describe the bug

It looks like we have a race condition somewhere inside the recovery code for persistent actors that can cause them to continue sending themselves RecoveryTicks even after the actor has shut down. Not entirely sure how to reproduce it, but saw some data from a customer that demonstrated that this had clearly happened and continued at a steady interval for some time afterwards.

To Reproduce

N/A

Expected behavior

No more RecoveryTicks should be sent after a persistent actor finishes recovering.

Actual behavior

It appears that in some rare cases, the RecoveryTicks never stop.