Grab buttons not working

Same problem, same platform, same device

Same problem did you ever fix it?

When you pull the trigger, does your character crouch down some into a squat position? Or they stay standing fully?

There were issues for multiple players in the playtest where the analog trigger values didn't register as a 100% pull, resulting in a crouch instead of a grab. The only solution I've seen for those players is to try a different controller. Usually it's only one trigger that causes the issue, but if neither are working the devs will likely need to adjust the calibration (or add a calibration setup) for the Ally.

I can't do grabs too. The character only crouches. Playing on ps4 with dual shock 4

I have same issue with dual shock 4, it's because my triggers are worn out.

If I recall from months back the people I saw having this issue also were PS based. Something about the dual shock triggers wearing out. I brought it up before and I'll add it here again. 

The dev team could easily add a controller calibration setup in the settings. Where a trigger pull can be registered based on the min/max values, then reformatted into the 0%-100% scale required by the game. 

This is super common in racing or flying games where wheels, joysticks, and pedals might be used, each one has different min/max values. It's only down to the game understanding what a full trigger pull registers, vs what is expected. I hope they add it in to allow more people to play with what they have available, instead of worrying about buying new controllers. 

workaround on PS4, to remap controller buttons on the PS4 system (not in game)
go to Settings, Accessibility, Button Assignments, Enable Custom Button Assignments
then select Customize Button Assignments

workaround on PS4, there are similar solutions for PS5 and Steam, to remap controller buttons on the PS4 system (not in game)
go to Settings, Accessibility, Button Assignments, Enable Custom Button Assignments
then select Customize Button Assignments

Sorry for the late reply guys. Still doesn’t work on my Ally, my character only crouches while I hold the grab buttons. 
I started using a ps4 controller and it worked eventually. Hopefully, they will fix it in the future!

Connected a ps4 controller to my ally and it worked. Otherwise nah, doesn’t work.