I have this problem too. The ONLY way I found works only works after you have picked your champ. In which you can either close your client and dodge the game, or wait a little bit until you believe the game has started, close your client, and reopen it. This prompts you to reconnect to the game that has just started.
It's really hard to determine when the match starts though, especially since now that there is remake you can easily get screwed over if you wait too long to reconnect. Prompting a massive LP loss. So I mean with this issue you could either dodge the match and wait 5 mins and wait out the low priority ques, or risk losing full LP for a remake if you don't join back in time.
It really is a pain in the ass though.