Ok so after doing a ‘thorough’ reading of the library’s documentation and comparing the example sketch, it was infact a very silly mistake of not including a couple of define statements in the beginning of my sketch.
The define statements are
#define USING_TIMER_TC3 true // Only TC3 can be used for SAMD51
#define USING_TIMER_TC4 false // Not to use with Servo library
#define USING_TIMER_TC5 false
#define USING_TIMER_TCC false
#define USING_TIMER_TCC1 false
#define USING_TIMER_TCC2 false // Don't use this, can crash on some boards