Ralph Mowery wrote:

You need to get the bulbs to match the ballast which in this case is
'instant start'. I have not bought any floursecent bulbs ina while, but
the last time I bought them seems that I could get a box of 12 for only
a little more than 4 bulbs.

If going to the LED type bulbs you may not even need the ballast. I
have not replaced any flourscent with the LED in the same fixture so can
not comment on that.

It would be nice if I can just cut out the ballast altogether.
Maybe the LED bulbs work with or without the ballast?
I'll call Feit tomorrow to ask if that's possible.