I have stepped in something terrible. Pretty sure its programming related.

=MOD(10-MOD(SUM(
2*(CODE(MID(B2,1,1))-48)-9*INT((CODE(MID(B2,1,1))-48)/5),CODE(MID(B2,2,1))-48,
2*(CODE(MID(B2,3,1))-48)-9*INT((CODE(MID(B2,3,1))-48)/5),CODE(MID(B2,4,1))-48,
2*(CODE(MID(B2,5,1))-48)-9*INT((CODE(MID(B2,5,1))-48)/5),CODE(MID(B2,6,1))-48,
2*(CODE(MID(B2,7,1))-48)-9*INT((CODE(MID(B2,7,1))-48)/5),CODE(MID(C2,1,1))-48,
2*(CODE(MID(C2,2,1))-48)-9*INT((CODE(MID(C2,2,1))-48)/5),CODE(MID(C2,3,1))-48,
2*(CODE(MID(D2,1,1))-48)-9*INT((CODE(MID(D2,1,1))-48)/5),CODE(MID(E2,1,1))-48,
2*(CODE(MID(E2,2,1))-48)-9*INT((CODE(MID(E2,2,1))-48)/5)),10),10)
https://www.excelforum.com/showthread.php?t=1028374