Hey, pretty much all ledge grab issues have been fixed since the last demo.
I'll list some ledge grab changes:
There is a new setting (on by default) which causes left/right to not let go off ledge grab.
Another new setting (not on by default) which allows you to aim with the direction keys, d-pad or the stick while ledge grabbing, also causing pressing down to not let go off ledge grab.
Added a momentum boost when ledge grab jumping allowing you to jump further horizontally.
Hopefully that should fix most issues with ledge grabbing, a new demo update will be coming out soon so you can test it out yourself. :)