Very little substantial information yet, although it can be easily get by performing differential diagnosis. E.g. disconnecting the motor power and operating the limit switches manually.
My first guess is contact arcing of the motor relays, causing electrical interferences. If it's a bidirectional drive, do you protect the relays circuit against shorting the motor capacitor by an appropriate dead time? Do you have RC snubbers for the contacts?
If the problem is only in display image, a quick and dirty solution could be to refresh the display more frequently or even to readback the content and perform a reset and refresh in case of differences.
Nevertheless it can be a pure software bug as well.