Wrong temperature on T1 while T2 is active
The temperature of T1 and T2 are different while T1 is active.
But When I switch to T2, the temperature of T1 is wrong(same as T2).
See in configuration->Tools if every extruder has set "Extruder Managing Temperarures" to the own extruder number.
If this is the case, go to console and enable ack and disable M105 filter and see what firmware says. Some do only report temperature for active printer. Correct answer will contain T0: and T1: in temperature report - if only one temperature is reportet as T: and we get no infos for other extruders to show.
It seems to be a Marlin bug in 184.108.40.206
My M105 response when T2 is active
20:58:49.981 : T0:25.37 /0.00 B:31.22 /0.00 T0:62.95 /250.00 T1:25.37 /0.00 @:0 B@:0 @0:127
Yes, returning in T0 the value from T1 is wrong. How should one know which extruder is meant if numbers are wrong:-) But from link you provided it seems they noticed already.