No, it's not typical. Whenever I've seen issues in the past, usually clearing cookies/cache resolves it. Try using a different browser and/or an incognito window to see if that helps.
Precheck has absolutely nothing to do with checking in online and everything to do with making sure your Known Traveler Number (KTN) is on your reservation
before check-in. See
here for more info. If your KTN numbers are not on your reservation, you should call in and have them added.
The TSA Pre-Check line is typically the fastest line, followed by the JetBlue Even More Speed (EMS) line, followed by the regular line, but this can change depending on the conditions, although, either of the first two are always faster than the regular line.