OK, been fixed for 0.219
To clarify how multiple swpaths work -
Multiple paths ONLY work for the SW Files tab.
Everywhere else (Media view, Newui, official Mame) - only the first path is used, the remainder being ignored.
Yes you are right. I'll work on that now. The reason it worked before is because the 2nd and subsequent folder was totally ignored in the SW Files tab. When that was fixed, seems this other bug appeared.