I normally convert RAW to DNG and rename to my name+date+original filename when I import to lightroom. But on last job this step got skipped without me noticing. I processsed and exported everything I needed, then noticed all the DNG files were named incorrectly. So I thought batch renaming in Bridge would save time. However, now Lightroom has an exclamation mark on all the files in that job. I tried selecting them all and clicking on the 1st exclamation mark in the batch, and when locate came up I selected the option to find nearby missing photos. All the photos from 2021 are in the same folder, but the find nearby option doesn't work. So far I have had to relocate each photo individually. Is there a way to fix this, as it will take hours (I could spend more productively) manually relocating each file individually and confirming that the file name has changed?
I wouldn't expect "Find nearby missing photos" to work in the situation where the actual filenames are different to the names that LrC is looking for, as it think it simply looks for files with the same name as the missing ones, which it obviously won't find. It works well if you've moved files outside LrC to a different location, but retained the original names.
The simplest solution would be to rename the files back to their original names using Bridge. That will restore the LrC links to the "missing" files, then you could do the rename to your prefered names using LrC instead, which is pretty easy to do and saves all that hassle.
The general method you outlined was what I tried. I renamed in Bridge again, and this recognised most files. But there were still quite a few exclamation marks on the lightroom catalog. The photos with the remaining exclamation marks turned out to be all the 3 and 4 star photos (the ones I chose to edit) and specifically those that were edited in Photoshop. That's because the batch rename I did in Bridge, omitted the '-Edit' at the end of the filename that Lightroom automatically adds to files edited outside Lightroom in Photoshop. Once I selected all the .psd files, I renamed them with the -Edit.psd ending in the filename, and that did the trick. Once I had all the photos renamed back to their original filenames in Bridge, I went back to Lightroom, selected all the photos from that shoot, and in Library mode, went to Metadata > File Name (which should say mixed), and clicked on the button to the right with the 3 small horizontal lines. Then I was able to batch rename the files using my Custom Renaming Preset.