If you have sync, and there is a problem anywhere, Shut Down Sync Immediately On All Devices to prevent the problem from spreading. Once the problem is fixed, perform the same repair on all computers/profiles before using sync again.

Are you using any bookmark add-ons/programs?

[v57+] Places Maintenance is built into Firefox.

Type about:support<enter> in the address bar.

You will find Places Database near the bottom. Press the Verify Integrity button.

When done, copy and post the results here.

y I think I did this correctly...

> Task: checkIntegrity + The places.sqlite database is sane + The favicons.sqlite database is sane > Task: invalidateCaches + The caches have been invalidated > Task: checkCoherence + The database is coherent > Task: expire + Database cleaned up > Task: originFrecencyStats + Recalculated origin frecency stats > Task: vacuum + Initial database size is 15360KiB + The database has been vacuumed + Final database size is 5120KiB > Task: stats + Places.sqlite size is 5120KiB + Favicons.sqlite size is 8800KiB + pragma_user_version is 52 + pragma_page_size is 32768 + pragma_cache_size is -2048 + pragma_journal_mode is wal + pragma_synchronous is 1 + History can store a maximum of 69658 unique pages + Table moz_places has 4374 records + Table moz_historyvisits has 4642 records + Table moz_inputhistory has 0 records + Table moz_hosts has 0 records + Table moz_bookmarks has 5341 records + Table moz_bookmarks_deleted has 0 records + Table moz_keywords has 0 records + Table sqlite_sequence has 0 records + Table moz_anno_attributes has 5 records + Table moz_annos has 24 records + Table moz_items_annos has 5 records + Table sqlite_stat1 has 18 records + Table moz_meta has 5 records + Table moz_origins has 2778 records + Index sqlite_autoindex_moz_inputhistory_1 + Index sqlite_autoindex_moz_hosts_1 + Index sqlite_autoindex_moz_bookmarks_deleted_1 + Index sqlite_autoindex_moz_keywords_1 + Index sqlite_autoindex_moz_anno_attributes_1 + Index sqlite_autoindex_moz_origins_1 + Index moz_places_url_hashindex + Index moz_places_hostindex + Index moz_places_visitcount + Index moz_places_frecencyindex + Index moz_places_lastvisitdateindex + Index moz_places_guid_uniqueindex + Index moz_historyvisits_placedateindex + Index moz_historyvisits_fromindex + Index moz_historyvisits_dateindex + Index moz_bookmarks_itemindex + Index moz_bookmarks_parentindex + Index moz_bookmarks_itemlastmodifiedindex + Index moz_bookmarks_dateaddedindex + Index moz_bookmarks_guid_uniqueindex + Index moz_keywords_placepostdata_uniqueindex + Index moz_annos_placeattributeindex + Index moz_items_annos_itemattributeindex + Index moz_places_originidindex > Task: _refreshUI

Looks good. What about my other questions?

sync, add-ons/programs . . .

When do you notice the bookmarks have changed?

As a precaution; Open the Bookmarks Manager; Press the Alt or F10 key to bring up the toolbar, and select Bookmarks. Hot key is <Control> (Mac=<Command>) <Shift> B.

Once the window is open, at the top of the page, press the button labeled Import and Backup. Select Export Bookmarks To HTML, and follow the prompts and save it to a HTML file. Copy the file to another computer/profile. Repeat the instructions above, BUT select Import Bookmarks From HTML.

https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks

I did shut down sync. Not going to activate it. Just keep them on my desktop.

It was about 2 weeks ago...maybe same time as a Windows update? Not sure.

Appreciate the help.

Extensions:

Adblock Plus - free ad blocker 3.4.3 true {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d} DuckDuckGo Privacy Essentials 2019.1.31 true jid1-ZAdIEUB7XOzOJw@jetpack Enhancer for YouTube™ 2.0.84 true enhancerforyoutube@maximerf.addons.mozilla.org Facebook Container 1.4.2 true @contain-facebook uBlock Origin 1.18.4 true uBlock0@raymondhill.net Video Resumer 1.2.3 true videoresumer@jetpack Bitdefender Wallet 21.1.12 false bdwtwe@bitdefender.com IBM Security Rapport 2.1.69 false rapportext@trusteer.com Security Software Type Name Antivirus Malwarebytes;Bitdefender Antivirus Antispyware Malwarebytes;Bitdefender Antispyware Firewall Bitdefender Firewall

The name of an automatically created JSON bookmarks backup in the bookmarkbackups folder includes a total item count (folders and separators included) and an hash value to prevent saving the same backup more than once. You also see this count in the Restore menu drop-down list.

• bookmarks-YYYY-MM-DD_<item count>_<hash>.jsonlz4.

Are the bookmarks still changing? Do they change in the same way? Does it look like random changes?

Are they changing when you are running Firefox, or do you notice it when the browser is opened?

Make a change. Then Close Firefox. Wait 20 seconds for the browser to finish closing. Then,

Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

It was a huge change but just once. I had a lot individual bookmarks in one folder and the day they changed, they were all gone and/or placed in folders.

Nothing has changed since. just not like it used to be.