Hey, that's very helpful to know. I'm semi-shopping for a battery to take out for ham radio things - looking at the River 3 and an Anker C300. Haven't dealt with EcoFlow before but Anker has taken care of me on a couple of warranty requests in the past. Thanks for the heads up!
For ham radio, I would strongly recommend buying some 12v LiFePO4 batteries, or a product based on them. It seems many of these consumer "power bank" products (like ecomax) are built on lithium ion batteries, and with that comes much less useful lifetimes, finicky care requirements, and much higher possibility of fire/explosion.
It's pretty easy to convert 12v to anything you might need. Most ham radios will work on 12v. I'm very happy with my DIY setup with 48AH batteries (24AH x2 in parallel) in a harbor freight dry box, some anderson plugs, and a cigarette lighter adapter that I can plug a real AC inverter into, and/or a nice USB PD based charger.
I'm sure there are companies out there that have this all packaged up as a product. I think the key is to look for LiFePO4 batteries.