Any issues with EPIRBs on domestic flights?

Checked baggage shouldn't be a problem. I've never tried taking them carry on as luggage. The only thing that have, that may be considered an issue, is batteries, but there's probably more in an old style laptop.

It's a different story for self inflating Buoyancy Vests with cartridges.

I should say I fly probably at least once a month with the gear.
Today the backpack had the Epirb , inflatable vest, nav tablet and sat phone and security had no problem.
Great VMG if you hold the Nav tablet up to the window though!

My airlines rules are:

EPIRB etc as checked baggage: on/off switch must be secured, e.g. Original packaging, switch taped over. Can be carried as cabin baggage.

Self inflating life jacket (That's the definition): 1 per person can be carried onboard/checked with up to 2 spare cartridges. You need to acquire airline approval, which can be a verbal approval at check-in and recorded in your booking.

Generally, consumer size lithium batteries are fine when installed in equipment, checked or carry on. It is loose spare batteries that is of concern in checked baggage and the rules are quite strict. As a general rule, never put spare batteries of any kind as checked baggage, always as carry on and boxed or packaged, not just loose in your carry on.