BLF's on Expansion Module has stopped working

[ETS]

I have an expansion module on a Yealink T48S Handset that is displaying red crosses on the BLF listings.
The 3CX is version 16 and is on a hosted Linux environment. The Yealinks are also running the current firmware. The BLFs used to show the extension status when commissioned 2 months ago and now they only show a red cross. There are some forum threads discussing changing the templates, however i don't know if the templates are accessible on Linux. Any assistance would be appreciated. Cheers

 

[SweetAction]

Try rebooting the phone.
Do BLFs on the main phone work?

 

[ETS]

Phone Rebooted, BLFs on the main phone work fine

 

[JohnS_3CX]

Hi ETS

Please share some more information like so https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

Especially the PBX version, whether it has all updates applied, and what version are your device firmware revisions, what model expansion and how many are in use (ie. EXP50).