User created Bitmask flag Enumerators are not correctly stored and retrieved from Blueprint Integer variable settings. When the Editor is restarted the value of the Integer's Bitmask Enum is set to None. When using a premade Enum such as EAnimAssetCurveFlags, the value will be set to the premade enum upon restart.
This issue was reported and tested in 4.21.2 (CL-4753647). This was reproduced in 4.20.3 (CL-4369336), 4.22 (CL-5159901), and Main 4.23 (CL-5236305)
Results: Bitmask Enum is set to none
Expected: Bitmask Enum should be the Enum created
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-70790 in the post.