Lfoc3 users that hard mount (lid/box etc) the Focer with M3 bolts seem to be using a wrong, too large diameter (nylon) washers under the nylock nuts. These washers are potentially supplied with a kit. It’s likely that the washers apply too much pressure on tiny components around the front row boltholes. Also using wrong washers can damage pcb traces around said holes.
Please be advised to use the correct type (pref smooth nylon) and correct diameter washers. These should be m3 with a maximum outer diameter of 7mm.