Pausing issue on a 2011 Nissan Altima 2.5s

Hello, was looking to get some advice for repair of my 2011 nissan altima 2.5s 2.5L (not a hybrid) The car currently has around 104,000 miles on it.

I bought the car earlier this year and everything seemed to be fine, no codes, no lights and it drove well. The previous owner was up to date on maintenance for the most part, the car has had three or four owners. At one point the car had a salvaged title, and its been in a few accidents. You can tell the bumper has been replaced at some point alongside other cosmetic issues. However, the car still drove fine.

I had taken it to a shop to get the CVT fluid drained and changed (not just flushed as I know CVTS can be sensitive) the fluid change was done. The mechanic doing the change stated the fluid was black, so I know it needed to be done. The car ran noticeably smoother since the fluid change, less struggle for acceleration (I had noticed the RPMS would jump before, but the car would be sluggish going forward, after the fluid change that resolved)

This brings me to my current issue, when driving the car now, anytime I come to stop, whether it be a stop sign or a light, the RPMS drop considerably, almost down to zero and I feel as though the car is losing power. I press the accelerator, and the car will not move. My foot could be to the floor and the car will not go, its as if there is a complete disconnect between the pedal and the car. The same thing happens in reverse, the car just pauses. It does not stall out, it is still running, but cant move. The way ive been getting around it is quickly shifting into park, giving a little gas, and then shifting back to drive. This usually causes the car to go right away.

It doesnt happen often, its inconsistent. Ill have days where it doesnt happen at all. Im posting here because im also getting the run around when it comes to getting it fixed. The same shop that did the fluid change, I brought the car back and explained the issue worried it could be tied to that. They kept the car for 9 hours, called me and said "we cant recreate the issue so you can come pick up the car"

I brought it to another shop I go to often and trust. They kept the car a week, told me I was experiencing a voltage drop, as low as 10.2, and they replaced my alternator. I also noticed that at night my headlights and interior lights in the car would be flickering so I suspected electrical as well. When I picked the car, the issue still persisted so I brought the car back. The mechanic scanned the car, could see no failures or codes, so his advice was "just keep driving it and call back ill see if maybe I can get you in again" (I had been waiting for this appointment for a month) He also told me that my battery was now bad because of the voltage failure. I had just bought the battery so he advised I get it tested now. I did, two seperate testers and the battery is fine. One test stated the alternator was bad, the one I had just paid for brand new at the shop. The car does not have any issues starting.

At this point im lost and looking for any advice/help. My brother and I plan to do as much work ourselves as we can before giving it back to a mechanic because two seperate shops now have claimed this issue is too complicated for them to solve. We plan to change the coil packs, The spark plugs, and possibly the fuel pump. My engine air filter is clean, my throttle body is also clean but I think I want to clean it again. My brother feels it is an air/fuel issue, but I wanted to see if anyone else had any ideas. I also plan to clean the battery terminals as well just in case.

This is my first time posting here, and if you read all the way through thank you very much and id be thankful for any advice you could offer me. Im moving soon and its very important to me I fix this car asap.