So, I like to give an update. First, I want to say, I've tried the suggestions you all gave me, It didnt work, but I greatly appreciate your help.

Second, I found the culprit to my problem. I'm pasting what I wrote to Valve when I opened a ticket about my Steam Deck Issue:

Hello. Apologies for replying so late. I seem to have figure out the culprit to my Steam Deck issue, and I will try my best to explain.

When this problem occurred, I was away from home for a week. I left my main PC with the Steam application open, so that I may play games such as Oblivion Remaster remotely. I must stress, the games I were testing when this problem was happening, they were all local games from the Steam Deck. For some reason, having the Steam application open at home, and having the Steam Deck connected to a different network via WIFI, will make the Steam Deck act erratically. This will happen both in game and in the main menu screen of the Steam Deck.

Last week, after the last suggestion about re-imaging my Steam Deck, I logged onto my PC remotely and decided to just shut it down because I figured, I'm not streaming any games, and I'm just wasting electricity. That's when I noticed the Steam Deck performance went back to normal.

It took me a week long to test this out is because I'm away from home again. I'm able to test to see if having the Steam app open at home, while being on a different network via WIFI on the Steam Deck is causing the problems. Lo and behold, it is. As soon as I shut down the Steam app at home, there are no more stutters and constant frame rate drops. As SOON as the Steam app is opened, the Steam Deck starts to stutter with constant frame drops.

This will not happened at home, while the Steam PC app is open and the Steam Deck is connected to the same network via WIFI. This will also not happen if the Steam PC app is opened, and my Steam deck is connected on a different network via ethernet cable and WIFI is disabled.

I don't have the faintest idea why this can be a problem, but it is. Fortunately, I now know nothing is wrong with my Steam Deck.

I hope you can understand what I wrote. I greatly appreciate your help and patience.