This is a known issue on XIQ Pilot and Connect. The fix will be in XIQ 23r1, which is tentatively scheduled for Go Live between 01/29/2023 to 02/06/2023
In the future and as per Christoph's previous response, for XIQ related inquiries, please use ExtremeCloud IQ board versus the WiNG board.
Please open this new topic on the ExtremeCloud IQ board versus the WiNG board.
I tested creating heat maps in XIQ today without issue and I could find any instance of a known issue.
Have you tried another browser, clearing browser cache, from another computer, etc?
Do you have several maps and is it happening with all?