This started rolling out in our org's tenant. There seems to be a regression of "keyboarding improvements" where you could tab across rows within Grid view as detailed in the following post:
Update information at the speed of type: Edit in grid view - Microsoft Community Hub
Keyboarding consistency | When you edit in grid view, you will have a faster editing experience that adheres to greater levels of accessibility. Navigate across rows and columns using the tab key. Plus, pressing Enter enables you to edit that field. Clicking Enter on a new row saves the new item. And pressing the Esc key closes editor.
- Roadmap ID: http://0.1.20.14/
And here:
May 2021 - Microsoft 365 US Public Sector Roadmap Newsletter - Microsoft Community Hub
MC252939 – Microsoft Lists: Grid view keyboard improvements
Microsoft 365 Roadmap IDhttps://www.microsoft.com/en-us/microsoft-365/roadmap?filters=&searchterms=70670
This new SharePoint feature will allow users to edit in grid view, and have a faster editing experience and greater levels of accessibility than before.
When this will happen?
Targeted release will begin rolling this out in late April and expect to complete rollout mid-May.
Standard will begin rolling this out in mid-May and expect to complete rollout mid-June.
How this will affect your organization?
This Edit in grid view feature will improve the speed and accuracy of how your users input and update information. Users will be able to navigate across rows and columns using the tab key. In addition, pressing Enter will enable them to edit that field.
Clicking Enter on a new row saves the new item, and pressing the Esc key closes editor.
This is rolling out default on with no admin control.
So tabbing is no longer a thing in Grid view?