Daystate Delta * Alpha Trigger Question..............Need Help

I'm a little perplexed over an occurrence which happened earlier today. I took my Delta Wolf out to shoot, for only the second time.
After loading a pellet, the trigger would not press. Safety in the fire position. I noticed that the trigger seemed to be further aft than I remembered. When I tried pressing the trigger again it fell out and into the grass. I was able to locate it, while thinking perhaps there might be springs or pins in the grass as well. Finding nothing else I went into my shop and inverted the rifle. I found that there is a track that holds the trigger. I slid the trigger assembly back into the track about midway.
I then shot three mags, and all is good. Or is it?
How / why did this happen, and how can I prevent a reoccurrence?
Any help would be greatly appreciated.
Thanks
 
Thanks ZX for the reply. Where is the trigger set screw located? How is it solved?
I meant to say it sounds like YOU solved it. Here is the fastener I’m speaking of:
IMG_1671.jpeg
 
Had a similar issue with my Delta. Moved the trigger all the way aft (on purpose) and the gun wouldn't fire. Unfortunately I stripped the screw on the trigger post when I tried to move the trigger back to a usable position. My fix was a little more involved than yours involving cussing and 3 disassemblies of the rifle. Not sure why they bother having an unusable section of the trigger rail.
 
Had a similar issue with my Delta. Moved the trigger all the way aft (on purpose) and the gun wouldn't fire. Unfortunately I stripped the screw on the trigger post when I tried to move the trigger back to a usable position. My fix was a little more involved than yours involving cussing and 3 disassemblies of the rifle. Not sure why they bother having an unusable section of the trigger rail.
All positions may (or not) actually be usable if the adjustable trigger blade is also horizontally moved upward. Not much is Sas proof though :giggle: