As a P365 and P365XL owner, I'm aware of the two primary issues that can arise when reassembling the gun. The first is that the takedown lever is not down, which is cured by lifting the slide stop, and the second is the safety lever near the sear is in the up position which blocks the slide.
I have a different issue.
The sear on my P365 is "up" and blocking the slide. See the pic below. Concurrent with this is that my takedown lever is in the down position and will not rotate counterclockwise and up. This prevents me from pulling the trigger and lowering the sear.
So how do get the sear down so it no longer blocks the slide? Christian cursing has not helped.
Let me just add that this occurred after I removed the thumb safety. I also removed the thumb safety on a different P365 and did not experience this issue.
I dropped my P365 off at the gunsmith. At first blush, even he could not tell what was wrong with it. There is something going on back near the sear that's blocking its movement. And on top of that, I jacked up the interface between the takedown lever and the bar to which it interfaces. That part is on me. So it is pretty d*cked up at this point, but I've hopeful it can be made right. Fortunately I have plenty of other toys to keep me busy in the interim.
Okay, lads, I got the P365 back from the gunsmith who (I think) said the trigger bar popped off the engagement to the sear or words to that effect. This would have occurred when I removed the thumb safety most likely. So attribute this one to a user-induced malfunction, which is far preferable to a random breakage. But a box of ammo later and My Precious is back on my belt where she belongs after supplanting the P365 XL from that esteemed role.
I need to further acquaint myself with the workings of the FCU so I can self-diagnose going forward. Honestly I've ignored it up to now.