Weird Ovulation

Hey y’all, so I’ve been TTC for about a year and a half & track my ovulation closely with a predictor kit. I checked it on Tuesday & i was at Low Ovulation, yesterday was High, then today was low again. Has anyone experienced this?? This has happened to me before a few times & I do have hormone issues due to Thyroid Cancer last year but one day of High & no peak is frustrating. Thanks for reading, I hope everyone is having a great week!