This is not a bug, but, imo, expected behaviour.
It is possible to set up an alias called network. and call it as an identifier (see /help $isid)
Alright, let's call it a feature. It is possible, but that doesn't give it an established purpose or make it especially useful. On the other hand, the purpose of a leading period in an identifier
is well established. (e.g. echo -q) Of course, I may have forgotten, or missed, something in the docs, so don't hesitate to correct any mistake on my part.
In the code I provided $network exists but $network. does not
(ie: there is no trailing period with the $network identifier anywhere in the code I provided).
Hm, nor is there one in my reply. I must be suffering from some form of dementia or senility in my old age

, because I don't remember making alterations.

In fact, that must have been the only alteration, because the rest of the script matches verbatim.
If you alter a working code and it stops working, then the problem is with the alteration of the code, not with mIRC.
I couldn't agree more, except for the last three words. The usefulness of a trailing period in an identifier is somewhat debatable, imo.
In any case, thanks again for sharing the wonderful script! Huzzah!