@aleksander-cane your heaters section has got a bit messed up, with the H1 definitions spread out over a couple of other sections. Try:
; Heaters M308 S0 P"temp0" Y"thermistor" T100000 B3950 A"Bed" ; configure sensor 0 as thermistor on pin temp0 M950 H0 C"out0" T0 Q11 ; create bed heater output on out0 and map it to sensor 0, lower switching frequency to 11Hz ; M307 H0 B0 S5.00 ; disable bang-bang mode for the bed heater and set PWM limit M140 H0 ; map heated bed to heater 0 M143 H0 S110 ; set temperature limit for heater 0 to 110C ;; Run Bed PID Tune!! Below is an example for a 300x300 bed M307 H0 A303.1 C356.7 D1.4 S5.00 V24.0 B0 M308 S1 P"temp1" Y"thermistor" T100000 B4725 C7.060000e-8 A"Hotend" M950 H1 C"out1" T1 ; create nozzle heater output on out1 and map it to sensor 1 ; M307 H1 B0 S2.00 ; disable bang-bang mode for heater and set PWM limit M143 H1 S280 ; set the maximum temperature in C for heater ;; Run Heater PID Tune!! M307 H1 A751.5 C196.6 D4.7 S5.00 V23.9 B0And make sure this comes before the 'Tools' section.
I think there may be other errors. Send M98 P"config.g" and post the response. Also repost your updated config.g if it doesn't work.