I installed a TWS dog leg rail on my PSA AK103 and almost every time when racking the charging handle the bolt gets stuck at the most rearward point. It also happens every 3-4 rounds when firing. A light tap to the back of the charging handle releases it. Does anyone have any idea what the problem might be?

Couple things so far:
The problem doesn’t occur at all with the stock recoil spring
The problem doesn’t occur if I raise the top cover
It is most definitely not getting stuck on the hammer, as it’s getting stuck past the hammer

Are you using the same spring on the stock and Dogleg guide rod?

Yes

I had an arsenal with a dog leg rail and the top of each side of the bolt carrier rubbed the inside of the top cover.  It wore a stripe of finish off each side.  After that, it ran as expected.

If I were you, I'd look at the underside of the dog leg cover and top of the bolt and see if you can see anywhere its been rubbing.  If so, either let it work itself out naturally, or you can lightly sand the cover in that spot so it wont rub the finish off the bolt.

ETA -
You can see the two racing stripes here.  One on the left and right side of the bolt carrier.  The curser is pointing to the left one.

Thank you very much. I’ll take a look and see if there’s any wear marks inside.

Where you able to get it fixed/solved?

I just ordered the TWS #33310 for (47/74) for my PSA AK103.

I ordered the ultimak (everyone said it will fit) ... Oh it fit after 1 hour of fiddling around with it and removing the interior heat shield from the lower handguard + minor mods to the handguard.

Sort of. I for the life of me couldn’t find any wear marks anywhere so I ended up putting in a recoil buffer as it stops the bolt carrier from moving just far enough to get to the sticking point. It’s not what I’d prefer as I’m leery of screwing with the action and I’ll admit I haven’t torture tested it but I’ve put about 200 rounds through it so far and nothing’s come up yet.

I had/have the exact same issue with my PSAK 104 and just like you, I had issues with the carrier sticking to the rear so I threw a buffer in it to limit the carrier travel to the rear. It seemed to work on the 104 and I haven't had any issues with it at about 350+/- rounds.

Then I picked up a PSAK 105 and with factory dust cover and recoil spring assembly, it hasn't had any stoppages. I then moved that whole TWS set up to it and I've had several failures to eject with multiple brands of ammo. I think it may be something with the buffer causing the issue on the 105 but without it, it has the same issue of getting stuck in the rear of the receiver in the TWS. Kind of a shame because overall, minus the needing a buffer installed, I really liked it on my 104. Seemed pretty solid and has really done an impressive job maintaining zero when I open it or take it off to clean.

If you will, let us know how well the #33310 fits on the PSAK. When I went to order mine from TWS they told me that they now recommended the #33317 for the PSAK because they found that the fit was better. The #33317 model is the for Century RAS which made me a little weary if they found similarities between the PSAK and the RAS receivers.