[BUG] invisible walls inside some doors in gzdoom 4

[light-and-ray]

GZDoom version

4.11.3, 4.12.2

Which game are you running with GZDoom?

Doom 2

What Operating System are you using?

Other

Please describe your specific OS version

Android, Delta Touch

Relevant hardware info

No response

Have you checked that no other similar issue already exists?

• I have searched and not found similar issues.

A clear and concise description of what the bug is.

In a mod "WolfenDoom: Operation: Arctic Wolf" it's not possible to go through a door on the first level (map09). Also I've found a guy with the same bug on WAD: Community Chest 2, MAP 19: https://www.youtube.com/watch?v=QZkDp6rpt24

I've tested all versions of gzdoom in delta touch:
v1.9.1: no bug
v3.2.9: no bug
v3.8.2: no bug
v4.11.3: bug
dev v4.12.2: bug

v4.11.3 VIDEO:
https://github.com/user-attachments/assets/c2644518-6a7c-41ec-9bd3-098a4e3c2178

Steps to reproduce the behaviour.

Explain how to reproduce

1. download http://lazrojas.com/wolfendoom/index2.html
2. load files:
   DOOM2.WAD
   ARCTIC.WAD
   ARCTLEV.WAD
   ARCTGFX1.WAD
   ARCTIC1.DEH
3. launch with cmd args: -warp 9 -nomonsters
4. find the only door that doesn't require a key

Your configuration

No response

Provide a Log

No response

[light-and-ray]

p.s. lzdoom 3.88b has the same bug

[prof-hastig]

You may have to disable MBF21 features in the compatibility menu. At least one old Doom editor set all unused linedef flags to 1 instead of 0 and this may cause some problems with newly added flags in MBF21.