Change:
if ($0 == 1) {
msg $1 EMOTE_HERE Thanks %nick for for $msgtags(msg-param-months).key months in a row! EMOTE_HERE
}
To:
if ($0 == 1) {
echo -s Debug for resub: $rawmsg
msg $1 EMOTE_HERE Thanks %nick for for $msgtags(msg-param-months).key months in a row! EMOTE_HERE
}
This will add a line into your status window everytime this part of the code triggers (which is only for reesub), the line will contain what twitch is sending, if it's not sending a tag with a name "msg-param-months" (which is what I assume is the case) either twitch is buggy or something changed, or you're misunderstanding/missing something