My current workaround is to have both 2.4 and 5 GHz networks configured for autoconnect. So after ungraceful shutdown, the first one to connect to will fail and LE will then just connect to the other one.
Few things you should try (if didn't yet):
Router without encryption (just for test), only WPA2 (AES and CCMP) encryption. Avoid WPA3 or mixed mode. Maybe is encrytion modes that isn't fully compatibile with iwd in LE.
If you or somebody near of you have a USB-wifi dongle, disable the onboard wifi (in config.txt) and try it with that.
Increase the wait for network time in the LE settings.