Unwanted Triggering in MOSFET driver circuit
make sure all gnds are common =0V
R3 is almost redundant but necessary because you have 24V instead of 12~18V Vgs ideal with >3x Vgs(th)max yet &lt; absolute max Vgs of 20V.


Probe gnd is probably fixing a gnd wiring error.

Since RdsOn is = 4 mohm (low) , Qgs is big 32mC which also affects speed of gate with R2=15k

With Trevor’s suggestion of R4=100 ohms Vgs max is now 24V(100k/(100k+R4) which MUST NOT exceed 20V. Thus he suggested R4=100k.  It can be any ratio that results in 12V to 18V with 2V safety margin on high side and low side to ensure low RdsOn.

Normally in high speed PWM designs Gate driver resistance is been 2000 and 200 x RdsOn or as per data sheet 2000x4 mohm =8 ohms so one might use a Vcc of 12V for Vgs drivers using 4V threshold type FETs