Actors that reside in TMap blueprint variables refer to the Editor actors not the copied UEDPIE actors (that we'd expect) when accessed in PIE. This is not the case in standalone; this only occurs for PIE.
Confirmed in Main CL 4329255
Example project available on UDN (too large for JIRA)
Result: The third line of the blueprint struct (which corresponds to the Actor in the TMap) reports that its WorldType is 2
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-63668 in the post.