One of the fluorescent lights in my apartment does nothing for long seconds or sometimes even minutes when turned on (then it surprises me when it suddenly comes on). It behaves as if there were some kind of timeout or something before it turns on. Eventually the glow switch comes on and fluorescent tube starts normally then.
I recorded a video about the problem where you can see it takes roughly 20 seconds for the glow switch to come on: https://youtu.be/Bw2DfIFjn8k
What causes this? Is it the problem of the starter or the ballast? The tube seems to be ok.