Problems with PDF form hours on Android phones

Hello,

I made a pdf form and in one of the fields put hours in the special format: 99:99.
On my android phone, it worked perfectly, already n another friend's cell phone that is also android, presents error.

Both are using the version of Adobe Acrobat Reader version20.6.2.14256.
What would be the problem? can anybody help me?

Ah, my android version is 10

Thank you.

Berg