Why is tab order incorrect in browser but correct in Acrobat and Adobe Reader?

I created a fillable form and set the tab order to by row.  This works correctly in Acrobat and in Adobe Reader but when I upload it to my website, all browsers use a different tab order.  I set the language as English.  It sort of behaves RTL in the browser, but is also somewhat random.  I have created many forms in the past and never had this happen before.  This form did start as a Word document which I used the Form creator to import.  Any ideas on how to force it to use the correct tab order?  Thanks.