It sounds like the amp/subs impedance is not matched. According to the published specifications
for the V1502 amp, it is only stable in bridged mode down to 4ohms, not 2ohms. You need to get the final impedance that the amp sees up to at least 4ohms or it will continue to shut down and eventually fail completely.
If your subs are dual voice coil and can be rewired so that each sub has an impedance of 8ohms, then you can safely parallel them to the amp like you have described. If they are single 4ohm voice coils, then you have 2 choices. Connect one sub to each channel or if you want to bridge the channels, then wire the subs in series, not in parallel. Wire the positive bridged terminal from the amp to the first sub positive, connect a jumper from the negative of that sub to positive on the other sub, and then the negative from that sub back to the negative bridged terminal on the amp. This wiring results in an 8ohm load to the amp and it should work OK without shutting down. But the power to each sub will actually be less than if you wire them separately to each channel.
Hope this helps.