I've stopped doing that because it gets tiring why I changed so frequently in recent years. It's not my fault places go bankrupt, startups do layoffs, or teams just up and dissolve after you join, and it gets tiring explaining that rather than discussing my experience, skills, and interests and the role at hand. It was a total mistake to enter into the startup world.
You're handicapping yourself with the lack of transparency. It just comes across as shady. Why are you worth the risk compared to the overflow of excellent candidates in this market?
You need to suck it up and share this information. Briefly explain each situation on the resume (i.e. "fixed contract ended" or "startup shut down due to loss of largest customer").
Edit: spelling.
> Briefly explain each situation on the resume (i.e. "fixed contract ended" or "startup shut down due to loss of largest customer").
There's not room, and it's ultimately irrelevant to my experience and skills.
Because your resume is better?
You really saving time by filtering those to whom it's important. Those who contact you would mind less about those missing months.
Yes, when you need every possible contact, you might be interested to approach things differently, but the question isn't how to match best the screening algorithms. And it's very sad thing to have to explain those months.
It's not fair, but it's true.
My automatic response there when filling out is "start date is always first of month, end date is always last of month".