I have Different modems but only XPON’s are not showing online…
You would need to provide a lot more info but you need to confirm whether the TR69 client is trying to reach your ACS…debugging on the ACS or tcpdump on the server.
This lack a lot of detail to be able to figure out why.
I presume those are all in one ONU / router. If so, maybe you have a tr-069 profile pushed through OMCI by your OLT. Normally, those are push only at boot so, if you change config, it should work fine until next ONU reboot.
Else, it’s hard to figure without more information and would probably be best to look out with vendor or, if gray market, maybe a consultant.
Personnaly, I always had good result with ACS descovery through DHCP option, even with cheap ONU manifacturer.