That sounds like your y endstop is getting triggered for some reason. This could be a fault in the wiring, the endstop, or the RAMBo itself. You can test if the limit switches on the printer are functioning correctly by first move the Mini’s bed to the middle of the Y axis so that neither of the limit switches are held down. Then connect to the printer using Cura, in the Cura console there will be a text box along the bottom of the window to enter in commands. Enter in the command M119 and hit enter it should show that both of your y endstops are open if one of them says triggered that will most likely be the cause of your problem.
Try this again with the bed pushed all the way to the front of the Y axis, and once with the bed pushed all the way to the back of the Y axis. Lastly disconnect the wires on both Y axis limit switches and try the test one more time, make sure to power off the printer when disconnecting these wires. If it is triggered even after it is unplugged it will mean there is something going on with your RAMBo or the wiring. You can narrow this down even more by unplugging the endstop at the RAMBo and sending the M119 command again, if after unplugging the wires from the RAMBo they are still triggered it will indicate an issue with the RAMBo.