Generic vs Synthroid for Hypothyroidism Treatment

Has anyone ever experienced that if they are prescribed anything other than synthroid for treatment such as the generics they don't work? When I was first diagnosed with hypothyroid my doc prescribed synthroid but would always put "dispense as written" on the script but eventually my insurance had to change and they will only cover generic...levothyroxine. I have not had controlled thyroid levels since. I have even been hospitalized due to my levels being too high almost causing my death( this past March). However prior to being hospitalized they had put me on the generic for the generic euthyroxine (sp). New doctor now and I am back on levothyroxine bc insurance won't give me synthroid. I am not getting younger and suffering bc of this. Sorry for rambling just curious anyone else experience this? TIA 🤔