All changes in plane should never be grout for this exact reason, only a matter of time before this exact thing happens. Remove it all and replace it with 100% silicone caulk in a matching color.

The grout joint in your first picture is too wide which is probably why it's failing. I'd suggest some waterproof molding silicone caulked in place to cover it.

Thank you so much. Would this be the correct caulking? This is what I used to patch up the small cracks, and the color is a great match. The three sides are okay. Not many cracks at all. Would you redo those with caulking too?
About removing the grout: Is this something I can do or best to hire it out?
Thanks again!

Or is there a better product than what’s pictured? A caulking and grout mix?🤷🏻‍♀️ This is okay for the fine cracks, but it does seem to lift around the edges over time. I just want a permanent fix.

That should be fine, it even says "permanently flexible for coves, corners, changes in plane and expansion joints" , which is exactly what the silicone is for.

Second the tape. ALWAYS.

Thank you to those who have responded. Yesterday, I dug a little deeper into the 3 other sides. Looks like those should be corrected too.🤦🏽‍♀️

Corners too. ANY AND ALL changes in plane are to be caulk and NOT Grout