MinimServer disapeared from LinnApp

[John1949]

Hello All
I wonder of I get can some advice please.
For last few months I have been enjoying playing my classical collection on Linn Klimax using Linn app for iOS.
This morning the MinimServer as media source has dissaperead from the app and I am unable to add it.
I have checked on my iMac and MinimServer is running with no issues. Yet, I can't add or see it to the Linn App.

Any suggestions please in simple words please as I am not IT geek

Thanks

John