Sometimes Singleton EvasionAbility like Flying or Intimidate do not work

[LevelX2]

Sometimes a creature can block a creature it should not be able to block.
E.g. a non flying creature can block a flying creature.

Concerned abilities:
Flying
Shadow
Intimidate
Fear
Reach

I added some new traces from the public server:

What do we know or presume:

• It's activated from some event happening. If so, the ability in the game stops working correctly.
• In other games the abilities work correctly.
• So probably something in the game classes is not correct.

What can we do to find the cause of this bug:

• Advance the trace to check possible reasons. Anyone ideas what to do?

Possible causes
Setting the Duration of the effect from "WhileOnBattlefield" to "EndOfGame" seems to reduce (or completely solve) the problem. Like the check if the permanent is on the battlefield is not always doen for the correct permanent, because the ability is a singleton it can't know the correct sourceId for sure.

[LevelX2]

So I hope I found and removed the problem with Mage Singeletons abilities like Flyinging and others not working sometimes. Under some rare circumstances the continuous effect (in the ContinuousEffectsList objects) were removed. So the abilities did no longer work, but the permanetes/cards still showing the ability.

I won't close this yet, but I'm pretty sure it's solved with the next update.

[drmDev]

Over 2 years old and no reports of this in... since I started contributing. We have many tests that cover these types of scenarios as well