M+ key rng protection

Had this happen recently, started doing M+ on my monk, start with a +2 city of threads, get a grim batol, finish, get city of threads again, finish that, get mists, finish that, get threads AGAIN

Seriously, this i not fun, having to run one dungeon over and over again for 50% of my runs is not fun. Should there not be some protection in place for RNG like this?