How can I activate the new Chrome tab management tools tab groups & grid layout?

I make heavy use of my tablet for research & typically have 200 to 500 tabs open. So I have been looking forward to the alternate grid layout and to Chrome Tab Groups for Android, which would make my life a lot easier. However these features, which I understood to be activated by default as of Chrome 88, do not seem to be available from my instance of Chrome (version 89). I have the file folder-style row of tabs across the top. I have neither a switch to grid mode button nor the hollow square with the number of open tabs inside. I have enabled the flags for tab grid layout, tab groups, tab group continuation, and tab group UI improvements, and restarted Chrome several times, all with no change I can see. I couldn't find anything on the Google help site that offered any glimmer of hope -- nor of discouragement. I can not even think of anything else to try. Help! I am running Chrome under Android 10 on a Galaxy Tab A. Oh, one more thing. I doubt this is relevant, but when I first got this tablet from Amazon, it took some work to convince it that its home was not in Mexico. Maybe there are still some Mexico-base settings causing a problem? Just a long shot.