Mismatched label-control associations in report despite multiple attempts to rectify

[Girraffa]

Hello! I am having a bizarre issue with labels in a report. I have five time fields that are used in four calculated fields that give intervals between the times in minutes. I have added labels that say "minutes" after each calculated field to specify units. When I go to associate these labels with the appropriate calculated fields I open up the dialogue and pick the control. However Access highlights a different field that does not have that name. What the heck is happening here? Also the labels keep jumping around on the report when I close and re-open it. I've tried just closing and re-opening Access and it keeps happening. I am very curious if this is a weird quirk related to calculated fields or if there's something weird I am doing.
the calculated fields are quite simple, all this code with different time inputs, this is in their control sources:
=DateDiff("n",[txtTimeSternal],[txtTimeRecover])
For example in the first picture I was trying to choose the control that is immediately to the left of the label, and when I choose the name of that control ("txtCalcDown") it highlights a different control that is named "txtTimeProcEnd" (see second photo for confirmation). When I scroll through the options it also highlights other controls with the wrong name. I can just leave them unassociated but I'm worried this is indicative of a larger problem so I figured I'd invoke the experts. Thank you for any help!

[June7]

Never encountered this. Shouldn't matter that the textboxes have expressions. Are you sure about the control names?

Can't have more than one label associated with the same data control. Not really necessary for label to be associated unless you want to set textbox as not visible and have the label be not visible as well.

Run Compact & Repair and if still have an issue, consider uploading db. Following instructions at bottom of my post.

[Girraffa]

I have triple-checked the control names. I didn't know you could only associate one label with a control, maybe that is where the problem lies: I will leave them unassociated. Thank you for the help, sorry for the delay in response!