We had something similar happen at a VIrtual Planning Meeting, however, when we investigated what the heck went wrong it transpired that between us publishing the link and the date of the meeting Microsoft had altered all their codecs, so the links wouldn't work. The annoying part of this was we tested the links the day before and the change came in overnight! This was confirmed by Microsoft and it played hell with our County Council that day as well!
BTW the link for the Councillors is different to the public link as we have full access, the public have to be let in and it was only the Public link that was messed up
However, we also request that anyone wishing to make a representation submit their questions, representations, etc in advance in case there is an issue, so everyone question was asked and every representation was made.
As we also record the meeting members of the public were able to inspect the meeting on our YouTube channel for transparency.
We are minded that the legislation and guidance both make it clear that it should be visible "if possible", in this case, we failed but we could still be seen being open and transparency by publishing the video, as recommended.