Persistent "Invalid Property Value" Message Upon Clicking of locked Comboboxes

I am experiencing an annoying little problem that I am struggling to find what is causing it. I hope someone can help me diagnose the cause as I'm not getting an error really nor does it break the code.

I have a userform with two comboboxes (in addition to some other controls) on it that I suspect are the culprits. All these controls are locked during the userform's initialization as I don't want the user to change anything presented. Information is only available to view at this point. (the boxes have default values in them for viewing)

With everything locked, when I click on either one of these two boxes, a box will pop up with an exclamation mark with "Invalid property value". OK closes the message, but all subsequent clicks anywhere on the userform, including the red corner X will pop up the same message. The x will close the form, but not without popping up the message one final time.

The user has a button they can click to unlock all the fields for editing purposes. The button simply unlocks all the controls. The user having done this, and clicking on one of these two comboboxes is given the list of values to select from. There are no "Invalid property value messages." associated with this click. Everything works ok when the default value is changed.

But if the user clicks either of those two boxes before "unlocking" them first, will result in persistent messages of Invalid property value. The userform shows it's displeasure when someone clicks on either of those two controls without first unlocking them.

Because there is no error, I don't know where the culprit is. I've eliminated those two comboboxes and started fresh think perhaps there was some property out of whack, and recreated them with no resolve.
There are change events associated with these two comboboxes, but I am under the impression these will not trigger unless there is a change in the existing value.

Hello Jenn68,

If you can post a copy of your workbook, please do. If you cannot because your data contains personal or sensitive information, please redact the information before you post. If you need to create a smaller version then be sure it mirrors your original workbook in layout and formatting. A workbook ids worth a thousand words.

Thank you!

Removed

To recreate the problem ...

From the visible sheet, click the blue oval to launch the form.
From the dropdown, choose an employee number
The View / Modify employee information button will be enabled. Press it.
Click the "Rate Code" combobox (it should be locked, you will get the arrow but no dropdown)
Now click anywhere else on the form. You should experience the message.