Using a thread for the notifications was also interfering/messing up the "show unread posts since last visit" as theymos told me.
That's just because the ICO spam slowed down
I used to see mainly ANN-threads, now it is indeed mainly your bot.
You don't have to do anything for this switch and you either receive your notifications through PM or Telegram ( as before )
I'm not sure if I'm going to like this change though, one of the problems with PM is that it doesn't show the latest unread, it opens the last page when I click it. If I receive 20 PMs per day from a bot, I can easily overlook real PMs.
I'll see how it goes first