The blue dot usually means the account has "Automatically add"
downloaded transactions to the account turned on, and there has
been one, or more, downloaded transactions added to the account.
Typically in that situation, the newly added transactions will
have a blue dot next to them. The dot will usually disappear
when the transaction is accessed.
Sometimes Quicken gets confused; there may have been no
newly downloaded transactions, or the downloaded transactions
may have had their blue dot removed prematurely by Quicken.
I do not believe the blue dot will cause any harm: if your
Quicken account is correct as is, I suspect you could leave
the blue dot there until the next download.
If you intend to try anything further, you might want to
make a backup - but do not overlay your regular backup.
One way to try to get rid of the dot is to toggle the
"Automatically add ..." downloaded transactions option.
If it is currently ON, turn it OFF, then back ON.
If it is currently OFF, turn it ON then back OFF.
Sometimes a Validate in between toggles may help.
If the toggling helps, but leaves the option not
set the wsy you want it, toggle one more time.
To access the account-level Auto Add option,
see the Online Services tab of the Edit Account Details
dialog for the account.