I don't think they make electronic ballasts for 8' tubes, (do they?)
Electronic ballasts are far more efficient than heavy iron, but bottom-of-the-line fixtures come with bottom-of-the-line ballasts too, some of which have operating temperature issues (both at high & low temp) as well as line noise susceptibility issues, etc. (Most are pretty good these days, but there was some real junk out there 8-10 years ago.)
If these are old-skool T12 (1.5" diameter) 4 or 8 footers with magnetic ballasts, the ground connections are critical, and it less-conditioned spaces like shops corrosion is common, so re-making all ground connections could fix the problem.
If these are 8 footers and ballasts are shot, replacing them with two 4-foot higher efficiency (with better color rendering!) T8 (1" diameter) fixtures can run about the same cost as a replacement ballast for the antique. The electronic ballasts all run at high frequency and are "flicker free", and the combined tube/ballast system produces ~90 lumens/watt instead of ~50 lumens/watt for an old magnetic-ballasted T12. T8s run cooler, look better, last longer, tubes are cheaper & more available, and they are cheaper to run. Cash invested in keeping T12 antiques going is usually money wasted.
If re-making all the connections to the fixtures doesn't make the problem go away and you're sure the wiring is good, move on (the world has.) IIRC, in CA under Title 24 it's even illegal to install magnetic ballasts now, since the systems can't meet the luminaire efficiency minimums.
Instant-start electronic ballasts are a bit hard on tubes, but run at higher efficiency. If this is somewhere the lights get turned on/off many times in a day it'll burn out the tubes quicker. Programmed-start versions may have a hesitation and start up at a slightly dimmed level ramping up to full-bright with 10-40 seconds, but they're ever so slightly lower efficiency (since they run a filament current in background, whereas the instant-starts don't.) In most applications the type of ballast-startup isn't very critical (as I expect it isn't in this case.)