You know that using Serial.prints in a ISR will cause issues, right?
Whiles the interrupt is being processed interrupts are disabled. Serial.print uses interrupts. Eventually there will be a clash.
Instead.
Make a volatile bool variable. Have the ISR set the variable to true when an ISR is done. Only code in ISR.
in loop()
if( isrdiditsthing==true)
do the isr thing set variable back to false.
When delay is active ISR does not work.