https://gitlab.synchro.net/main/sbbs/-/issues/489#note_3068
So there might be a socket leak in that scenario. If running ircd separate from sbbs (i.e. via jsexec), you still may need to increase the open file limit, but in this case, you're probably detecting an issue because your limit is low(er).
--- SBBSecho 3.20-Linux
* Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)