I’ve been (re-)searching a lot, even this one Again: Supervisor: blocked from execution, no host internet connection
but nothing helped. From CLI all given links (even the mandatory ones shown on HA help page) have been working, ‘downgrading’ did not work, because HA supervisor didnt find internet, …
So I tried the small steps and first installed a SD card with minimal linux, booted from that (so the NVME wasnt mounted) and after double-checking the NW config incl. DNS I manually downloaded the zipped HAOS 13.2 image to the SD card, and wrote it to the nvme via dd. I read somewhere, that there have been reported issues when Windows 10+ writes the image to the NVME, in this version no Windows is able to interfere! Then I edited the eeprom config to change the boot order (because I wanted to leave the SD inside) and finally it booted from NVME to a working HA 
!
Hope this keeps working🤞🏼