How to get pop-up text to show up?

I am using Acrobat Pro 2017 to create a fillable form with tool tips.  I am using a Dell Latitude E7450.  Form users will use the same machine or a Dell Venue tablet on a docking station with a mouse attached.

I used the Edit PDF tool to create tool tips for all the text boxes that needed them. I closed the Edit PDF tool and hovered over the text and it worked.  I sent it to some test users via email.  The form didn't show the tool tips for them.

Next, I used the Prepare Form filed to created buttons with no labels, borders, or fill so they wouldn't show up.  I didn't make them hidden. I placed them over the text that needed the pop-up help, then entered tool tips for each button.  I tested the form by hitting the Preview button.  They showed up for me.  I sent it to some test users via email.  The tool tips did not display for the test users.

Next, I used the Prepare Form tool to create text fields and used the popup text I needed as the default value.  I made all the text fields I created hidden.  Then I created buttons with no labels, borders, or fill so they wouldn't show up.  I didn't make them hidden.  I set the actions on each button to show the corresponding text field on mouse enter and hide it again on mouse exit.  I used the Preview button to test the form.  It worked for me, but it flickers rapidly and doesn't always stay open when the mouse is over the button.  I saved it and sent it to test users via email.  It showed the pop-up text, but it flickers rapidly and doesn't always stay open when the mouse is over the button.

Next, I used the Prepare Form tool to create image fields of the text I need to have show.  I re-create all the buttons with no labels, borders, or fill so they wouldn't show up.  I didn't make them hidden. I placed them over the text that needed the pop-up help, then entered tool tips for each button.  I tested the form by hitting the Preview button.  They showed up for me, but it flickers rapidly and doesn't always stay open when the mouse is over the button.  I sent the form to some test users via email.  The tool tips did not display for the test users.

Finally, I changed the actions on the above form to show the image on mouse down and hide on mouse up.  It worked for me with no flickering.  It didn't even show up for the test users.

I am now throwing in the towel and asking for help.  My questions are these: WTF?  Why is this not working for other users? Shouldn't all of these methods work on at least the other user's Dell Latitude E7450 machines?

Can someone please help me to get this to work?