9015 Printer IPv6 address conflicts when Proton VPN active

[testlab]

My 9015e printer is attached to my router via CAT5 and a second switch. It receives an IPv4 address 192.168.1.244 from the router's DHCP and works without trouble. This IPv4 address is displayed in the network section of the printer's control interface. This is also the only address displayed in the "Embedded Web Server.General.Network Summary" page.

However, the Windows Test Page gives an IPv6 address for Printer Location as http://[fe80::e270:eaff:fe60:78d0%6]:3911

As soon as I connect to the Proton VPN from my PC, the Windows Print Manager reports that this printer is "Offline" and I cannot print from my PC. However, as soon as I disconnect from the VPN, the printer returns to normal status and prints just fine. I have tried troubleshooting this with Proton support (including enabling split tunneling for 192.168.1.244 ).  They now say "..it seems that on the PC the printer is configured to be reached via IPv6. Instead, you should put the IPv4 of the printer in the Location field as http://192.168.1.244:3911/"

My question is, how can I force the printer (and/or Windows) to use only an IPv4 address?

Thanks in advance

[testlab · Accepted solution]

After further poking around, I learned that the IP version can be set in the HP printer configuration app (aka "Embedded Web Server"), as follows:

Open the Printer Configuration App in a browser, using the printer's IP address.  For example http://192.168.1.234/ 

Ignore the browser complaints about this site being un-secure. Once the app is showing:

1. Click on Network tab
2. Enter your Printer PIN (conveniently hidden inside the printer's cartridge door)
3. Scroll down to Network.Network Protocols.
4. Click on Network Protocols
5. Under General Network Protocols, tick the button for "Enable IPv4 only" (see below)
6. Click Apply
7. Exit the app
8. Restart the print (power on/off)

I found this was sufficient to place the printer's address within the VPN's locally mapped addresses, and I am now able to print from my PC while the VPN is active.