I've noticed mostly with Excel - in complex formulas or odd ball case things can work differently. Or course, this may have been with older versions.
that was the issue with an earlier version of Open Office.
As long as you were just entering data into a table, Open Office would work. If there were any calculations, or pop up menus in the Excel, you would get garbage in Open Office.
Supposedly, the newest version of the Excel module in Libre is much improved. We will see.
The biggest issue with the OO Word program is you had to remember to save the document in Word format, the default was some OO format that was the computer version of Esperanto - and people using Word couldn't open it.
Some editing features wouldn't play nice between OO and Word, but they were advanced features that I was able to avoid using in the documents I was preparing.
One thing neither had the Wordperfect (the thinking person's WP program) had was the ability to insert the bar code for a zip code into an envelope or label. They still don't have that ability without some add ons, as far as I know.