Matchframe to multicam clip links to edit locked sequence

when I matchframe to a multicam source clip, the multicam clip that loads into the source monitor is frequenly not editable - it's showing up as a read only clip, despite there not being any editing locks that apply to the clip.  This means that I can't choose any different edit points on the clip or change camera angles.

My work around is to copy the timecode of the point in the multicam clip where I'm trying to add a mark in point; reveal the sequence in it's source project, manullay load the same source multicam clip, and then I can edit from the clip (then apply the timecode to get to the point where I want to add my new mark in point)

This is happening with multicam clips that are stored in projects that are separate to my editing project.

I've worked out that Premiere Pro is treating these clips as though they are edit locked

This started happening on 25.5.1, and when it was suggested that I try using the Beta versions (v26.0, builds 19 - 23), the problem has persisted