Lightroom 10 and canon r5 raws, now exposes properly BUT big problem...

Hi guys the Canon R5 used to underexpose files by about half a stop.  With the latest camera raw and lightroom it has corrected this BUT on files that are already imported to lightroom before the update, they only 'update' to the new raw files when you zoom in 100% in develop module, going back to the library module keeps that look but then switching back to develop module makes it automatically dark again.  Surely a bug, but I've got 3 full weddings that have all been tagged now and am hoping that there is a simple solution to having lightroom see the proper raw file (the brighter one) so I can edit as per normal and have the end export come out as I see it.  Thanks.