Why does my car stall when I switch from reverse to drive?

Do you have a CVT? If so I suspect a transmission problem. What is a gap in the transmission? Subaru may repair this for free as it is a known problem. https://www.carmd.com/Tsb/Download/101541/075074

Either a long delay ("gap") in shifting from P to R or D, or a stall at idle are indicative of a failing CVT, notwithstanding Grasshopper's head stuck in the sand.

Dude you need to be learned, they all do this, even with 5 miles on the odometer. Literally deal with this everyday someone new wondering why this happens and it is NORMAL for there to be a delay especially from reverse to drive.

A short delay yes. A long delay is not normal.

Short = less than 2 full seconds.

People perceptions of short and long are never the same, and I can say in my experience they have longer delayed shifting than any car I've driven, but what do I know I only work on fifteen a day. Pull them in and out, drive up on a hill even slight incline put it in reverse with the brake applied put it in drive If you let off the brake immediately like you would any other car it will still have delay roll back and feel rough once engaged, every car drives differently if you can't handle it or understand it then don't get one. I can't stress it enough if it take longer than three seconds to engage then yes you have an issue.

I have only driven two almost new Subaru's with the CVT and to me they did not delay anymore than an automatic car. I would have noticed a long delay as I was paying close attention to the transmission.

I've driven a thousand and they are all the same under 100k if you want to talk statistics.

Huh? SOA squeezed by the phenomenon of dried piston seals in the old 4EAT by telling customers that a delay less than 3 seconds was "normal". The high fluid capacity and AWD complexity help to create a 1-2 second delay when shifting. That's what ST is attempting to allude to. Three full seconds is a LONG time...and I've yet to experience ThAT long a delay with the newer CVT. Only bad bearings and torque converters seem to plague this modern wonderbox. You seeing anything else, ST?

Yes I'm seeing that you can't except being wrong with all I've seen the way you talk to anyone on here, just because you can claim to be intelligent and get your information from your garage work or google doesn't make you that, and I don't have to let you one person that clearly bashes everyone so that you can feel that your the right answer effect what I know and try to make me agree with your forceful accusations, someone gets butt hurt much?? Certified any?

And I said more than three seconds is a problem so thank you for agreeing on that

Huh? "Dude you need to be learned" isn't bashing?