Your previous setup does not matter at all in any way, (factory reset will remove all previous configurations and you can not re-pair devices before first doing a factory reset of them somehow). There is no easy or seamless way to migrate Zigbee devices between different gateways/hubs/bridges/controllers, so you are just going to have to start from scratch. (The only thing that would have made it easier is if you had been able to remove all Zigbee devices from the previous gateway/hub/bridge/controller they were joined/paired to as doing that would have factory reset those devices).
You just have to bite the bullet and try to factory reset each Zigbee device and then pair/join them one by one. Unfortunately, you do need to check the manufacturer’s website for each device and search other community sources like Reddit if there are other methods for factory reset, (and yes for most devices without buttons and batteries that sadly most often involve different variants of flipping the light switch on and off in a specific timed sequence for each specific product, sometimes even different on similar products from the same manufacturer, but fortunately I do not think many devices require jumping or arm flapping).
The main tip is to begin by adding all of your main-powered Zigbee Router devices to start building out your Zigbee network mesh to extend range and coverage so can then reach devices not close to the Zigbee Coordinator (before adding any Zigbee End Device such as battery-powered devices).
I highly recommend you read + follow tips and advice in these community guides because compared to commercial hubs for specific brands you should really learn a little more about how Zigbee works to optimize your setup and Zigbee’s limitations to work around as it makes everything simpler when following best practices:
- Zigbee buyer's guide
- Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage
- Migrating from a Philips Hue Bridge to the ZHA (Zigbee Home Automation) integration
- Not many people know that... A random collection of Zigbee trivia
- A to Zig - a Zigbee glossary
That is not always needed, and it might be easier if you can factory reset your devices following other methods if possible. But as a last resort, a Philips Hue Dimmer Switch (or Lutron Connected Bulb Remote) may be needed for some troublesome Philips Hue devices that have previously been joined to another gateway/hub/bridge/controller, see → https://www.home-assistant.io/integrations/zha#add-philips-hue-bulbs-that-have-previously-been-added-to-another-bridge
Might be worth buying one if it will prevent factory reset via jumping or arm flapping 