Do the Strife maps have custom weapons?
When T.U.C.Q. was in Legacy it used a DEHackEd patch, and Strife's levels likely would have too.
In order to get T.U.C.Q. working properly as an IWAD in GZDooM I had to redo the weapons as part of the DECORATE lump, and define the weapon slots. I am pretty sure that would break any weapons using DEHackEd. In fact, I found that weapons created in DEHacKed were not being selected, because GZDooM was ignoring them in favour of the DECORATE versions. For example, in (the current unreleased versio of) DeiMWolf (uses the same sorts of changes as T.U.C.Q.) there was a problem with switching weapons. If I picked up the MP40 I could not select it. Eventually I discovered it was because the pickup was being applied to the DEHackEd version of the weapon, but I was only able the switch between the DECORATE versions. If the Strife levels are using DEHackEd based custom weapons, this is probably what is happening.