Motors do not work together

Hello everyone, I am using two motors for x and y, a NEMA 17 and a NEMA 23, each with different drivers (A4988 and TB6600). They are powered by the same external laptop power supply and for logic 'estop out'. One motor functions perfectly fine, while the other does nothing. However, if I unplug one motor from the parallel port, the other motor starts working. I am unsure if this is a PC fault or if I should use separate power supplies. I'm not entirely sure where to start troubleshooting. The controllers are connected only through two power cables and one logic 5V connection, so I don't see how disconnecting one motor could affect the other.