Detection zone grids are working for my v2 cams with Cam Plus Lite using both 2.50.x and 3.x.x apps running Cam v2 firmware 4.9.9.3006. Not sure what the difference is with my setup that allows the grid feature. 
I have an active V2, too, that I use to record scenes with very bright light sources. Its detection zone is a grid, too.
If the firmware versions are the same, I wonder if the affected V2s have somehow updated with a slipstreamed version? Highly unlikely but possible.
Would someone with the bad V2 be willing to try flashing the new firmware?
Bump…
Bueller? Bueller?
Still nothing, eh? Disappointed…
Just realized the issue today and thanks all the discussion here to help me understand it’s an real firmware/app change.
Looking forward to see if the feature could be brought back
Still no response from Wyze on this?! What a bunch of clowns! The inability to have a grid selection means I have to narrow the larger box style zone to such a degree to avoid constant notifications from tree branches waving that I also miss detection of some events that are important. I’m now searching for alternatives and am considering just getting a Tapo brand camera that will easily integrate with my existing Tapo devices anyway. Sayonara, Wyze, I won’t miss you.
3x V2’s in use here, all on 4.9.9.3006 f/w
2 of them show the detection grid, 1 shows the stretchy box
So I’m slightly ahead 
Monitoring thread for an update
2 of my cameras have went to a rectangle box.
It’s No Bueno! Tried all the suggestions to fix it and nothing. Wyze needs to send a fix out for this glitch.
Same here. Got 11 V2 with firmware 4.9.9.3006. One of them displays rectangle instead of grid.
Is time to fix this issue, most user need the Grid detection zone or even a manual drawing like others brands. The Box is a nightmare. Thanks!
So there’s still no fix? I have 4 v2s running the same firmware to have the nice grid to have one single block.