Due to a problem in the Intel® Quartus® Prime Pro and Standard Edition software with the Windows* OS scaling resolution configuration, the time bars may not appear while using Signal Tap Logic Analyzer on 4k resolution monitors.
To work around this problem in the Intel® Quartus® Prime Pro and Standard Edition software, change the monitor resolution to 1920 x 1080 and restart Windows* OS.
This problem is fixedstarting with the Intel® Quartus® Prime Pro Edition software version 21.1.