Trying to diagnose a hardware issue

What the Issue Is

I first noticed an issue with CoD Modern Warfare about 4 weeks ago when the announcer didn't say anything for the whole game, or guns wouldn't load in. Then this happened more frequently and the game freezes on the final scoreboard after 1-3 multiplayer
games. Sometimes out of the lobby the game takes very long to load and eventually tells me it timed out.

There have also been similar issues in Fortnite where guns and textures don't load, and the character is unable to do anything except move around (and shoot from an invisible gun).

Additionally in certain games like Rocket League, it is impossible to browse through my car loadouts because they take too long to load in.

What I Have Tried Already

I have rest my Xbox, by keeping the games and also by deleting them and redownloading them.

I have cleaned all the dust out of my Xbox (this involved me breaking the warranty seal, but my console is around 5 years old so warranty didn't apply anyway). This actually improved the Xbox's performance, but didn't help with the issue.

I have tried an offline OS update, which didn't achieve anything.

The fact that none of these helped with my issues lead me to believe that there is a hardware issue.

I was wondering if anybody is able to identify the cause of the issue, and suggest a way to fix what is wrong? I would buy a new Xbox, however I plan on buying the new model when that comes out later in the year and so would prefer not to have to pay for
two consoles in one year.

Edit to add: I have the original Xbox One that I got around Summer 2015 (can't remember exact date)

:)