really annoying bug thats costing me ranked matches ! tell me if this bug is known.

Since I got onto the newer client. One game randomly I alt + tabbed out of the game when I ult tabbed in I couldnt use a single skill or I would have to mash 50 times to get one to come out. I went into the normal client and now it occours randomly during games some games ill load in fine others ill load in and cannot use a skill so im forced to exit the game and reconnect and even then sometimes that doesnt fix it. RITO PLS