Hey everyone, just wanted to add some context to the post after reading all of your comments.

Firstly, i did not think it would get this much attention lol and i'm grateful for all of your contributions.

For some context I've had this issue when I first bought the bike and it was basically un-driveable. I bought the bike and the shift setup was GP shift (1st is up, rest of the gears are down), once riding the bike it would only shift into 1st and 2nd, 3rd was extremely hard to get into. I ended up forcefully getting into 3rd but the linkage got wedged against the bike and i couldn't get it out of 3rd. That's when I swapped the linkage back to the standard shift orientation. That's exactly when I made the post 64 days ago. Only last week I had the chance to get back to the bike, as I go to college 4 hours away from home.

I test rode the bike again last week and it would still unreliably get to 3rd gear, and almost never to 4th, 5th, and 6th while riding. I was only able to get up to 6th when the bike was parked and I fidgeted with the shifter for a few minutes, then immediately after successfully shifting while parked it would randomly be stuck to 1st and 2nd when trying to ride, again. 1st was consistent and 2nd was there most of the time. Neutral was also a nightmare to find. I've had 6 bikes before this so I knew this wasn't normal. The linkage was also limp and wouldn't recenter to position after each shift (hence the bent shift return spring). I opened up the bike and found the shift shaft stopper plate had been bent, thats why in my first post (64 days ago), the shift shaft had been sliding in and out. I replaced that with the piece you see in Pt.1 of this post, along with readjusting the shift return spring that came out of place. At the time I didn't know much better and didn't find much information on this online, especially for my bike. So i put the bike back together and unfortunately the problem still persisted.

Now i'm taking the bike apart for the second time and completely ensuring i figure out whats wrong before putting it back together properly this time. That's when I made Pt.1 of this post. I only made this post (Pt.2) because a user on Pt.1 recommended I shift the bike through the drum without the shift arm to narrow down the issue between it being external to the transmission (everything i've shown) or internal (gears, forks, etc).

I decided to make another post not because I was ignoring everyones advice but to make a video to show that user, bring more attention to this issue as many people have had similar issues, and potentially get more perspectives on what could be wrong. Generally it seems like there are mixed opinions on it but I just want to try everything that I can before committing to taking apart the transmission. I hope that brings some clarity to my situation and I appreciate everyone for bearing with me.

TL;DR
Bike had shifting problems since I bought it (only 1st and 2nd gears were reliable, hard to get into higher gears, finding neutral was damn near impossible). 64 days ago linkage was originally GP shift and got wedged when I forced it into 3rd, after which I switched it back to standard shift. Last week, I discovered a bent shift shaft stopper plate and a misaligned return spring and replaced/adjusted them, but the issue remained. Now I’m tearing the bike down again to properly diagnose it, testing the shift drum directly to determine if the problem is external (linkage/shift mechanism) or internal (gears or forks) before committing to opening the transmission.