I had the same issue... (wrong credentials error from within HE ecobee integration app 'HEEBIA' - despite working directly on ecobee site)
I found a work-around that finally worked for my instance (note I tried many things, so some of this may or may not have attributed to the eventual success):
EDIT: Start at Method 2 (Step 9) - this appears to be the solution to the password sync issue.
Method 1 (I don't think this is what actually worked, but I did these steps first):
- Disable 2FA from ecobee app (not sure if this is necessary)
- Log into ecobee from another browser tab (not from within HE ecobee integrator app), click 'remember me' on ecobee login dialog
- Now launch HE ecobee integrator app again, this time should not get the log-in dialog, and goes straight to eco-bee webite (mobile view)
- From drop down menu on ecobee site you will likely see not logged in > click log-in
- enter credentials and log-in.
- Browse to your thermostat (top right drop down menu)
- check to see what integrations are linked
- Close window - hope that HE ecobee integration app proceeds to next step
Continuing from Method 1:
9. Ensure log-out from ecobee website (to force HE ecobee integration app to require log-in)
10. Launch HE ecobee integration app
11. attempt login - if fails, this time request reset password
12. Following ecobee pw reset process - enter the SAME existing password that you use for the site.
13. re-attempt login from HE ecobee integration app (this is where the password finally was synchronized and worked for me)
14. Continue set-up...
I am unable to reproduce the mis-sync'd passwords issue, hope this helps someone however...