I’m glad to hear the eWeLink app is now working properly for you. Sorry to hear you’re running into trouble getting your devices re-linked with Google Home though.
A good first step would be to check if you have LAN Mode enabled for those devices, and if so, try turning LAN Mode off. Then attempt linking to Google Home again. Toggling LAN Mode off can help rule out any connectivity issues between the device, app, and Google.
If turning LAN Mode off doesn’t resolve the problem, let me know. We can then look into other potential causes.