Clearblue digital solid smiley - but other OPK say no??

Sarah
Hi guys, 38 and TTC six months.
Track my periods dilligently and have been ovulation testing too.
So on thurs morning I got clear blue digital flashing smiley on CD10 - thought that was a bit early but whatever.
Tested again that night and it was a solid smiley!
However I've done a different kind of ov test, non digital, and it says no LH surge?
Confused now. How accurate are the digital tests?