no entrance to portal room

when I reach the nearest stronghold from the origin, I cannot find the portal room, even though the stronghold is large enough. Only upon breaking through walls do I discover that the room is completely sealed off. This happened to the last 2 seeds I played in a row:

2127059200
-2009834222

I also had this couple of times before( before 1.18)

 

I dont think it is the desired behaviour to have this room completely sealed off, or am I wrong?