Why is you game freezing after the prologue concluded?

(This is an approximate sequence of events) I was playing 7th dragon III code VFD, and was on chapter 2 when, during an enemy encounter, the game froze on the battle transition screen. Thinking it was a glitch I shut off the system and played something else. A few(?) months later, I tried to play it again to progress (I was at the point where you could A) make a second team and B) progress to the forge.) After starting the area, I talked to an npc you could rescue, but after the conversation, the game got stuck on an infinite loading screen, which forced me to exit the game. I attempted numerous times to progress, where the game would infinitely load in generally these three places: after talking with the soldiers to access the forge area, transitioning to the forge area, and talking with the previously mentioned npc. The game would also still be frozen on a black screen when entering a random battle as well. When the game froze, the bottom screen was still displaying, and the music would still play for battles, while the over-world freezes would have the loading animation play on a loop indefinitely (I checked and let it sit while playing another game and after 30-40 minutes ish, it was still “loading”) and the music was still playing. This also affected a save that was on chapter 3. Hoping that the glitch was caused by the dlc corrupting the saves, I uninstalled the dlc, tried the saves again (I think), deleted the saves, and started a new save. After progressing through the prologue, however, the games’s music shut off after I made a new party member, and would not turn back on. After engaging with two boss fights, and seeing the conclusion cutscenes, the game would enter the loading screen like the other freeze, but the loafing animation would be frozen too. After another attempt where the music kept turning off, I left it alone for a day or so, and when I tried to play it again, the music kept on running, but the same conclusion kept reoccurring, but the music was still playing. I have tried almost every I could see recommended, barring a sd card reformatting and a full factory reset. I even took out the motherboard of the cartridge to see if anything was damaged. Other games, such as my copy of Monster Hunter 3u, still works properly. Does anyone have a diagnosis and possible fix?