The videos on far right of page is what is playing next.

Have you searched Extensions page for something like that. ?

Are you logged on to Google in both cases?

Thank you for your troubles.

No. But I think why you wonder.

I try a moment ago the same video and the playlist changed. See enclosed images.

I'm baffled why the play list change differently in the browsers

Never seen that. Viewing in Tiles.... Anything in the Youtube Menu the 3 lines left upper side ?

When you read the tiles, starting at the left side, from up down; it will match the play list on the you tube page at the right side just below the auto play button

OK. So is this issue solved ? If so please mark something as the solution and if not please detail further what issue you need help with.

The only two ways to solve my problem are:

1. -Firefox use the same method as Chrome, but the play list changes randomly.

2. - If they use different methods, either there is an option to select one method or there is no such option.

I am not sure, but leaning to case 1.

Thank You very much for your troubles

In a sense my issue is solved

It is not Firefox that determines what is shown in the sidebar and suggested in the player once you have finished paying and possibly clicked Cancel, but it is YouTube that generates the page and decides what is displayed. It is quite possible that different browser give different results and it also depends on what cookies are send.

You can clear the related Google cookies in both browsers and see in what way the results change.

Clearing the cookies of youtube in both browsers was the solution. I got the same playlist in both browsers.

Thank You