Timing on turning our primary into a rental

[Matt Lindsey]

I live in Temecula, CA (Southern CA). I'm considering turning our current primary into a rental. I already have a rental property in a nearby city that has stable tenants. If I rent my current primary out, collect the first month's rent and security deposit, are the tenants allowed to stop paying rent for month #2 and on if they suddenly make a claim that COVID-19 is causing financial harm? Is there something in a rental application that could ask that very question - "Are you currently experiencing financial hardship caused by COVID-19?" Or is that illegal?