Yes.

• Run whichever of our apps you have.
• Click in the menu: Help ▸ Trouble Zipper.
• For Question X (Extra Extension Tests), answer "No".
• For Question B (Bookmarks and Documents), answer "Include Bookmarks and Documents"
• In the list which appears, select all of the apps you are syncing, by holding down the ⌘ key after your first selection.
• In the "Please explain..." section, tell us the day and time that things blew up, or when you noticed that things had blown up.
• Send me the resulting .zip via MailDrop, Dropbox or whatever, as instructed.

All of our apps export to and import from browsers using the same program code, so it does not matter whether BookMacster or Synkmark.  My suggestion is still to clear out all items from browsers and start with a clean slate, as explained in my previous reply.

Hello, MJP.

We don't have any known issues like that with BookMacster 3.0.3.

1.  Not common, but it you have BookMacster on more than one Mac or are using anything else to sync Safari to Chrome, ensure that you do not have a sync loop.

2.  Your Safari bookmarks in iCloud, or maybe Chrome bookmarks in the Google cloud, could be on the fritz.  The short version of how to fix that is

• Switch off syncing.
• Get all of your bookmarks into BookMacster as desired.
• Delete all items in Safari and Chrome bookmarks.
• Wait an hour or so, or maybe as you say "so often" and ensure that no items reappear in Safari or Chrome.  If they do, delete them and repeat.
• In BookMacster, export to Safari and Chrome, or enable syncing if desired and export to Safari anc Chrome as prompted.

We also have a more detailed version of those instructions, for Safari only.  I've never seen this issue with Chrome, but you may as well do both at once.

(Since we occasionally need to help people with stuff like this, I'd appreciate a follow up so we can increase our expertise and increase out insight into the black box of Apple's iCloud Safari syncing.)