drop list combo box_can not select item as the cursor is the cross

Hello! I have a problema related to combo boxes. I have a 3MB file with 5 combo active x comboxes (1 texto box and 5 drop list). These combo are dependente and are linked to name ranges.
The problem is that very often I can not choose a item from the drop boxes as the cursor is the cross (design mode off). I can solve that by turning on and then off the design mode. IS there any other solution as this file is to be used by others? Thank you, Nuno

Hi! Thank you!
I think there are no code running as I have very few code. The main code is in timeline worksheet. The combos are in dados worksheet.
So the thing is that when I change from worksheet dados to another one and then I return to dados, the combos are no able to select a item.. the cross appears.
I share a resume version of the file!

Hi! The fact is that the original file has 3MB mainly because of the size of the tables that feed the combo boxes. The vba running on the sheet of the combos is to actualize de listboxes as they are dependente (without the vba the lists were not actualize).
The thing is that if I remove the vba listbox_change the list are not going to actualize as I change the value in the dependente combo boxes.
Should I join the combos in a userform or use a simple data validation or not using the filter function which is feeding the name managers or...?
thank you!