Purchased M4P files Cannot be converted or burned
I have some older purchases from iTunes dating back from 2004 through 2012 - when iTunes offered the 'plus' without DRM in 2009, some of those older purchases automatically converted or offered conversion to the new DRM-free versions - however some did not. Strangely, some music I purchased through iTunes into 2012 are still showing as protected, and can't be converted or burned either.
I tried every possible method to get some mp3 versions of those songs I legally purchased from iTunes, but nothing has worked. I put them in a playlist and attempt to burn an MP3 CD-R, but it says they cannot be burned. I can't convert them to MP3. I don't get the 'cloud' icon for those songs, so I can't delete the Protected version and re-download a non-protected version from the cloud. Nothing has worked, and I'm stuck with 38 songs I purchased legally from iTunes, that show up in my purchase history, but that I cannot burn to a CD or convert to MP3 to play in other locations, such as my car.
Can anything at all be done? Are there other options I haven't tried yet - after trying the 'burn the playlist to CD-R trick, and with no cloud download icon for any of these? I just want to put the music I paid for on an SD card to play in my car. I don't have iTunes Music subscription or Match subscription - I might be willing to try 'Match' if there was a guarantee it would pick up these purchases and give me a DRM-free version...but don't want to waste the money if those songs won't convert. Strangely, some songs on one album have the cloud icon, while other songs on the same album don't.
iPhone 8, Windows 7