fillable word doc is not letting me fill it out

Hi I created a word doc and put in fillable text boxes and locked the document to only allow editing of forms.

I have then uploaded this document to a ftp server and made a shortcut on the home screen so that it can be easily accessed every time one of the staff need to complete the checklist it will make them save a copy of the document under the corresponding work order and then allow them to edit however when i click on the text box it allows me to enter 1 character then says this is not a valid entry. If i use the prediction feature and click on a word it allows the word to go in there but i can only type 1 character manually.

I have tested this on widows xp and it functions as intended and have tested on andoid and functions as intended but the on the ipad it is not functioning the way i want to it.

if i can provide and further details please ask and thank you in advance for your help in resolving this