Connection rejection

Hello,
my computers (WIN 10) are organized in a network. One of them is the server for the others. Remote access protection is activated in “AVAST premium security” on each PC.
So far, access has been trouble-free. Each PC can access the shared folders on the server computer.

I just installed the latest version 2 days ago. Since then, Avast on the server has prevented access to my other PCs.
However, the IPs of the authorized PCs are well defined on the server.

Are there any other parameters to set? Or is this a bug?
In the meantime, I’ve removed the “remote access protection” to continue working.

Thanks for your ideas!