This is quite long so just buzz over it without trying to keep track of the steps. Then read it slowly and see if you can reproduce what I am Seeing.
The issue I see is that the Buttons under search that I see are:
Primary, Transactions, Updates, Promotions.
I am NOT seeing the "All Mail" Button.
Here is what is do and see it:
Only one button at a time has text.
Start by tapping on the Primary button on the left, it shows the word "Primary"
then click on the "Shopping Cart" button and it shows the text "Transactions"
Then click on the icon that look like a comment "Text on multiple lines and pinches to a point at the lower left it shows the text "Updates". Then the "Bull Horn" icon, click it and the text "Promotions".
The "All Mail" button/Icon is NOT in the List. If I place my finger on the Button/Icons and try to slide them Left or Right they move but just a little.
If I click on the "Promotions" button/Icon I get the "All Mail" Icon and the other four are just Icons.
When I hit the "Primary" Icon the "All Mail" Icon on the Right appears and has Text.
If I click on the "All Mail" button/Icon I get the "Primary" Button/Icon and the other four are just Icons.
It's like the "All Mail" is the LAST on on the right and the only was to get it to show is to Click the "Primary" Button/Icon. Also if i hold a Button/Icon ( that has text ) for more than a few second the release it ALL of the Icons collapse and one of them has Text in it.
Starting with "Promotions having text you can click on each Icon from Left to Right ending on "Promotions" then click the others and they all work. To get to the "All Mail" you can click ANY Button/Icon that has text and the "All Mail" icon has Text.