Controller still active but not jogging

I noticed today that *sometimes* especially after a longer run, the machine does not jog anymore after the program is finished. Not with the screen buttons, not with the hardware jog buttons and not with the wireless handwheel. But some other functions still seem to work like spindle on and off and the LED flickers as usual (have not tried just running another program). Re-connecting or resetting the controller does not help. The only way to get the jog function going again is closing the PC software and re-starting. It is not a huge problem because the controller keeps the position and I can run the next program without problem. But a bit annoying anyway...