Beryl AX VPN / DNS issue with 4.6.2

I have updated my Beryl AX to 4.6.2. My setup is that I have a permanent connection to a Wireguard VPN setup as Global Proxy. (It connects to my home, where I have pihole DNS filtering.) My DNS server settings are 'Automatic', and it lists both the ISP and VPN DNS servers.

I noticed straight away that things normally being blocked by pihole were showing. After playing around, resetting back to 4.5.16 (everything went back to normal), and reinstalling 4.6.2, I isolated it to this new setting:

Allow Custom DNS to Override VPN DNS

The way this is phrased would appear to me to mean:

Off = VPN DNS is used
On = Custom DNS is used instead of VPN DNS

However, when it is 'Off' it appears to use the ISP DNS server, loading things that should be blocked when using the VPN DNS.

When it is 'On' everything works as it should / used to, i.e. the VPN DNS is used (not overridden).

Is this a case of lost in translation, or a bug? I have searched the forums and note that there have been some issues, but I'm not sure any have been quite like this / mentioned the Beryl AX specifically.

Do you have "Custom DNS" configured? "Automatic" is not custom dns.

If not, then either option on or off, you should all use the VPN dns.

I do not - it is set to Automatic.

However with the setting 'On', it uses the VPN DNS.
With the setting 'Off', it does not - I presume using the upstream / ISP DNS.