I cannot add files to my email!

Hi I have recurrent issues with mailspring that I cannot add files to my email. It happens randomly. I use Linux mint and mailspring does not give me access to all folders, not to my phone but even if I copy the photos on my desktop it does not give me access.
Apart from a nice design it seems to be too glitchy and I really have second thoughts about going back to Win 10 and Thunderbird.