I had written keywords in DPL5.0.1 to a bunch of test images and saved the .dop sidecars. Thy contain the keywords as shown below.
After updating to 5.0.2, the keywords did not show, no matter what I did (run an index, manually read settings and metadata), also, the keyword list is empty.
Possibly related:
Issue found with iMac 2019 and macOS 11.6.1.