trader_4 says...

If it were me, I'd at least look at new LED fixtures.
Fluorescent has the worst color light of any choice.
LED is available in a few wavelengths and most look
much better and use less energy. If you're willing to
paint the ceiling too, they have shapes and styles that
look 100 times better than the ugly rectangular old
stuff.

I have six fixtures (12 tubes) in the kitchen above a
dropped ceiling with plastic lens sheets belown the
fixtures. I'n afraid that changing just the bad ones to LED
will make things look funny because the light intensity,
color or distribution will be different. So I think if I
change any to LED, I'll probably have to change all of them.

Reading up on this, it appears there are a number of options
for LED tubes, some of which require a ballast, and some
don't (but at a higher price). So I think I'll have to
spend some time at HD or Lowes with my calculator.

I would say though that it doesn't make sense to me to go to
the expense and trouble of changing to LED and still end up
with a ballast. So it looks like the ones that connect
directly to mains would be the way to go, but again I guess
that depends on the price.

I guess one other option would be changing over to
conventional T8. But I suspect I would have the same
appearance issue as with LEDs if I only switch the bad ones.
And I'd have to invest in new ballasts.

I went into one of the fixtures tonight and basically just
broke and remade the connections, and it works fine now.
But it may not tomorrow. We'll see. The wire nuts were not
snug, and wouldn't snug up. So I mashed them. And there are
no starters.