The issue mainly stems from bad tax accountants and the fact that I have investment accounts in the UK where the tax year is different so collating the info for the US tax year is harder. I have lived in other countries and it has never been a problem.
The accountants I have had here have been completely unable to read basic investment account data. They have fabricated numbers out of thin air, repeatedly made the same mistakes over and over.
Despite paying them to do it, I ended up manually doing all the calculations and writing a script to work out my income/divs/gains in the format they need and they still managed to copy/paste the data incorrectly.
Have you had a similar experience?