Why are my Items updated when I didn’t make the changes?

This issue is called double synchronization which often leads to the incorrect product data update on the channel.

How M2E Pro works if Magento Multi Source Inventory is configured

Our Development Team has provided the relevant improvements to make M2E Pro and major Magento update — Multi Source Inventory (MSI) — compatible.

I can't choose certain attribute because it is not presented in the list

Please learn how to make Magento Attributes available for the selection in M2E Pro.