Same image sequence one offset but not the other plane A assigned material A that has an image sequence.
plane B assigned material B with the same image sequence.


When i change the frames offset of the image sequence in material B both are changed

How to offset only one without effecting the other?
Make sure that materials is different. If it is not true, you will see a number near material name:



In this case press on digit to make independent copy

Next step - image node. Click on digit here:



Also mesh data can be linked:



So do you understand the rule? Remove all digits to make independent copy of material, image, mesh data.