Riddle me this

LH surge on cheap Amazon OPK (my personal fave)... I never use the expensive ones for this very reason, but no surge on the Clearblue?! Both taken within the same time frame. This is the one that is supposed to detect two different hormones Eggwhite cm, high soft open cervix... unsure of BBT because I’ve really slacked over the holidays... anyway, what would cause this?! I’m annoyed cause now I don’t know if I can trust the cheapies... or if I should not be trusting the digital?!