The blinky is one of the slowest (lowest current) balancers there are and has no volt reading. It's hard to tell what the state of balance is without a volt reading on each cell , but eventually it "should" balance them perfectly.

If I had those packs I'd check the individual cell volt readings 3 times.

First as soon as I rx them, second after the charge (they should all be exactly equal and about 4.1-4.2 volts) and then finally after the flight to give an idea of cell capacity match.

Without these readings and without having the packs it is anybody's guess , but my best two guesses are that the packs are starting to degrade OR the blinky is on the blink.

You got other packs that are just fine? on the same equipment? May I also suggest a cheap 50 watt charger or a digital balancer for your T-J.