I forgot to include screenshots from File Explorer with my query

re :Many folders are no longer visible in Inbox - image showing what Tbird displays.

I presume you are talking about subfolders to 'Inbox'. Please post image shwoing what Thunderbird displays in the Folder Pane.

Tell the forum the names of the folders that do not display.

Are they these folders and subfolders contained therein? Three folders that start with the name 'DETROIT' Although judging by the names you may have been creating new folders based on the year. So really only need to see DETROIT 2014-16 Client - NYBC

Possibly the following, 2019 SIPA CAPSTONE 2020 CAPSTONE CITI but it is possible you have created new folders for them with a similar name. eg: SIPA 2019 CAPSTONE and SIPA 2020 CAPSTONE CITI

Thanks Toad-Hall. I’m talking about a gmail folder and its subfolder. I’m attaching screenshot of Folder Pane and the two screenshots from the Profile. Missing from the Folder Pane screenshot are some folders that are visible in the screenshot of Mail/gmail-1.com but ALSO missing from the Folder Pane are some folders that are visible in the screenshot of the subfolder Inbox.sbd.

Missing from Tbird folder pane but visible in Mail/gmail-1.com are folders named APTS, Brookings, Client-DC-TRC, Client-Ravvoliba832527, DETROIT 2014-16, NYC, NYS2010, Personal PRESS2011, PRESS0cd4c312, PublicSpeaking, TAMC, TECH, Yonkers2012, zzOLD Regina, aNYC DOF Commish Group. Missing from Tbird folder pane but visible in Inbox.sbd subfolder APTS, DETROIT 2014, DETROIT 2014-15, DETROIT 2014-16, 2019Kitchen I really appreciate any help from the Community.

edited for formatting

Stans solved this problem. Somehow, the attribute of some folders had been turned to "hidden"