Bolt locking open early with Maxim buffer

[blaster113]

Ive been running a Maxim buffer for about a year now and really like it.  Lately I’ve been getting malfunctions where the action locks open with rounds in the mag. Magazines are new Brownells Colt pattern mags with new Taylor Freelance spring, follower and basepads.  The mags ran flawlessly with an old MBX dual spring buffer.  Anyone else have this issue?  Mag springs too soft?
 

Stock 32 round Brownells and Duramags run great.  Thanks

[Ner]

is it default maxim or did you change anything especially the spring ?

[blaster113]

The Maxim buffer is straight out of the box, no mods