unable to update 2 out of 5 homepod minis to ios 18 beta

I have the latest public iOS beta 18 installed on my iPhone 14, iPad and 3 HomePod minis. They all are working fine. However, I have another 2 HomePod minis which will not update to the beta no matter how hard I try. Normally used as a stereo pair, I have ungrouped them, reset, restarted, etc. to no avail. If I open the Home app and go to beta update, it will list my other minis but not these two. If I open the two problem minis they will play however the alarms at the bottom of the page do not show and contains a message to update to latest software in home/settings. Doing this it claims the software is up to date. The minis do not show up in the beta update tabs. All the minis do show up as bridges though I am not able to assign a priority bridge.

[Edited by Moderator]