The headphone jack suffered a wear that is causing the device to understand that there is a headphone connected (even if it doesn't exist), I've tried to do all the correct cleanings possible but it didn't fix it.
Notifications play perfectly on the speaker but media don't.
Is there any app or method to make this switch manually?
It seems the easiest way to go is to use an app, like Disable Headphone Fix Earphone for example, to disable the headphone jack and make your audio only output from where you want.
My first instinct was to look at your audio profiles and disable it that way, but that way may not be as simple as it sounds possibly requiring you to put your device into "developer mode" to be able to access certain features your device may or may not have depending on your version of Android.