Avalanche VNC connection to Pi Bookshelf

I just moved from Buster(Raspbian) to Bookshelf(Raspian) on a pi400 and now cannot connect to VNC server using Avalanche.
Internet advice said to uninstall RealVNC as it has stopped supporting password authentication and to install TightVNC which still supports password.
This has improved matters a bit. I can now connect via vnc client on a mac but no luck with Avalanche on RISC OS.
One difference is that the mac has provision for specifying a userid, but I cannot find this option for Avalanche.

Check the release notes.. for the new OS release?

Particularly the changes to VNC encryption support – they may have changed¹ the defaults

¹ Changes in ports/encryption etc are a bit of a pain at work just lately. Suppliers changing stuff in their upgrades and the field based support staff not having a clue is the first thing we think right now.

Check the release notes.. for the new OS release?

Interesting read and gives a good clue about the VNC change:

WayVNC VNC server used instead of RealVNC when running on Wayland

Suppliers changing stuff in their upgrades and the field based support staff not having a clue is the first thing we think right now.

Argh! How about “supplier releases new ‘minor’ upgrade (something like going from version 1.2.13 to 1.2.14) that removes 32-bit compatibility, but doesn’t bother to document it in the release notes”? Only after I logged it as a bug did they update the documentation.

For bonus points, when I advised that the auto-updater shouldn’t be installing a 64-bit version on a 32-bit machine, they acknowledged the problem but refused to fix it (something like “but fixing that would require releasing a new 32-bit version with a fixed updater, and we’re not doing 32-bit any more”).