having this problem with 2 games so far recently bought, real vr fishing and down the rabbit hole. In middle of download it just stops and have to click install again like nothing downloaded. Also never had this problem with my quest1..
i think i might have found a work-around through a reddit thread i found about this problem as it seems to be quite common. Disconnect and reconnect your wifi in the quest2 every half hour or so till the download is finished. Worked for me now to install a game. Hopefully oculus are working to fix this issue so wont need to do such things