Mine is a 256GB WiFi only model, same model as the author’s, and I have verified independently by using another WiFi only M4 iPad that the issue is reproducible. I have opened a feedback regarding it (FB15665218) with a sysdiagnose dump.
One of thing I noticed while investigating the device’s syslog output is that there appears to be a codesigning issue with the wifid daemon:
[corewifi] MISSING ENTITLEMENT, will not continue (pid=69 proc=aonsensed bundleID=com.apple.aonsensed codesignID=com.apple.aonsensed service=com.apple.private.corewifi-xpc req=GET COUNTRY CODE entitlements=[com.apple.private.corewifi.countrycode])
Given that like you said - WiFi only models do not have GPS modules and rely on WiFi to infer the current location, this might be related.
[Edited by Moderator]