Occasional Contributor
We have shutdown skype for busines server .
Done below steps
1. changed all the dns configuration
2.changed coexistence mode in teams admin center to teams only.
3. Enabled external chat settings in teams admin center.

Now when users tries to chat with external user it shows "chat is disabled , This user is currently using Skype for Business".

when I checked teams admin center and powershell command I got following results.

Teams admin center :
HybridOnPremEnabledUserWithSfBAnd Teams License
Powershell results :
Hosting provider : srv:
Interpretedusertype: hybridonpremteamonlyuser

Only for few user external chat is working and the configuration is as follows
Teams admin center :
HybridOnlineEnabledUserWithSfBAnd Teams License

Powershell result:
Hosting provider : sipfed.online.lync.com
Interpretedusertype: AADConnectEnabledonlineteamonlyuser

Please advice how to fix this issue.