Main Calibre Program Blocked by Avast Firewall

[HairyScot]

All of a sudden Avast on my laptop has decided to block Calibre when I attempt to connect my android tablet as a wireless device via the wi-fi hotspot on my wireless adapter.
This is something that has been working fine for years.
Now I have to turn off the firewall to synchronise Calibre Companion on the tablet with Calibre on the laptop.
I tried setting a Default Rule of ALLOW ALL for the program but to no avail.
When Calibre is blocked "Host Process for Windows Services" also gets blocked.
I receive no error messages.
Windows Defender and its Firewall are inactive.
Attached pics show the Avast screens.
Any ideas or info would be greatly appreciated.

[Asyn]

Set the Avast Firewall to private mode and reboot.

[HairyScot]

Set the Avast Firewall to private mode and reboot.

Makes no difference.

I have had to follow the path used by many others experiencing this problem:- Turn off avast firewall and turn on Windows Defender Firewall.
Guess who won't be renewing come February 2020.

[Asyn]

Try the Geek Area settings, mentioned here: https://forum.avast.com/index.php?msg=1505540