Pomodoro Clock Failing Tests 14 & 15

Hi all, hope I can get some clarity. I have been doing the pomodoro clock and practically it works (ie it counts, cant go over 60 minutes, cant be <=0 minutes, plays a beep, resets etc but I am failing 2 tests (14 & 15) with the same error:

Timer has reached zero but didn’t switch back to Session time
Error: Timer has reached zero but didn’t switch back to Session time
at file:///C:/Users/rober/OneDrive/Documents/GitHub/pomodoro/FCC_Test_Script.js:154:276550
at file:///C:/Users/rober/OneDrive/Documents/GitHub/pomodoro/FCC_Test_Script.js:154:264486
at Array.forEach ()
at MutationObserver. (FCC_Test_Script.js:154:264467)

any pointers greatly received

my GitHub page is https://robwuk.github.io/pomodoro/ and repository is https://github.com/robwuk/pomodoro

any input anyone?? these 2 tests have me stumped