PGS subtitles not working rc4

I have a few Mkv files with PGS subtitles that worked in rc3 but stopped showing subtitles in rc4. SRT subtitles are still working fine in rc4, so this only applies to PGS. I tried 3 different Kodi setups and the issue appeared on all 3 (they were all windows machines but different hardware)

Thanks in advance for any help