Yes, too many to count. The most recent was a SIG P290RS in 380ACP. Had been trying to find one for some time, finally found one that was new old stock. Only made one range trip. It just didn't fit me well. Didn't feel right. Cleaned it and sold it immediately. Lost some $ but I never fret about that when trying something new or indulge my spontaneous nature. Plus I don't have a big selection of rentals I'm interested in locally.Agree with those who said too many guns bought and sold over the decades.
However, in the spirit of the thread - those that just "didn't work out".
The worst was a new Kahr P380. The FFL (my range) talked down the Kahr so badly, said they were nothing but trouble in his rental fleet and also for many customer that it really freaked me out. Never even fired it, sold it off.
Whenever I try 380 pistols, its always with the thought of upgrading caliber over the 32ACP P-32. Never works out with the exception of the Beretta Pico. Carried that for awhile but in the end it's always back to the trusty P-32.