Handle should move freely with some resistance and able to be pulled with one hand
No resistance likely shows the locking/pull rods have detached from the handle internally
Jamming or very hard to pull likely something has jammed in latch
IF Jammed closed Push forward firmly on faceplate, while pulling the handle (on each side of the drawer) to help take load off the mechanism allowing the mechanism to disengage fully.
Ensure nothing has fallen down in front of draw assembly and could be jamming from underneath
Check the dust cover is riveted down securely and is not lifting or getting caught.
If unable to be opened If the unit has items inside drawer remove items to get access to front
If unit has removable floor, follow this step
If latching closed is an issue inspect front latching point to ensure all fasteners are secure and the "dog bone" has not fallen out / come loose.
Inspect the 'dog bone' to ensure this is tightly secured.
To access the latching mechanism;
Remove all bolts holding the internal cover plates in place with a 5mm hex
These may vary in appearance depending on build date
Ensure the spring is secured in place and the 2 x M8 Bolts are fully tightened.
Once covers are off attempt to simultaneously unlatch both sides by hand to open drawer
This can be done by someone reaching in from each site or by sitting inside drawer.
Latch mechanisms should move freely by hand, Check for anything jamming and ensure springs that pull the latch back are in place
From inside drawer pull on locking rods - if these are extremely loose and can be moved easily lengthways, likely they've jumped from inside the handle mechanism
Likely next steps will be removal of faceplate to access the handle/rod mounting
When closing both latches should click into the latched state with minimal force
If jamming when opening and closing inspect for any visible wear points or signs of damage, Ensure debris or any loose items are removed from internal drawer roller track