How are you accessing your profile folder? Through the settings>help>More Troubleshooting? JUst establishing whether the profile with the 'bookmarkbackups' you're seeing is your actual active profile.

I don't know why deleting places.sqlite would help, I would have assumed the opposite, but you say you 'followed steps' so I guess the theory is that it had gone faulty?

This is an odd one, but did you try restarting your computer? I lost stuff once but for no known reason they came back when I restarted. You should restore that places.sqlite first though.

Otherwise, I would hope you had backed up your bookmarks at some point using the export?

Sorry, I see you say you had a json file with the bookmarks, so I understand you can't get this file to load under the bookmarks import>restore>choose file?

Perhaps (first without restoring the places.sqlite, and if it doesnt' work , then do restore it) youthen might need to create a new profile and copy your old profile and paste the data you need from there to the new profile (after closing Firefox down first, of course). Then you should have it all back, but in a new profile.

Thank you for the process. I will go the new profile route in the morning. Yes, I did follow the steps from a Mozilla support bookmark recovery page. I did restart the PC several times. Unfortunately neither did the trick. I am okay with creating a new profile. Appreciate the help.