Check what IP HA is expecting and then check the IKEA hub to see if they match. If you have DHCP turned on for your hub then when you moved it it might have gotten a new IP. Easy fix its the case, just set a static IP on the IKEA hub for what HA expects and then restart the integration.
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Or make it old school and use the hostname instead of the IP.
You were correct, though I couldn't find a way to update HA with the new IP. Ended up just re-configuring the Ikea integration, weirdly it's forgotten half my bulbs.
Like others said, most likely your HA IP changed, had this happen recently in a power outage. Need to either set them to use hostname or make the HA machine have a static IP.
if memory serves me correctly, Trådfri lights run on Zigbee, no? I don't personally use Trådfri but I've got Hue bulbs on my Home Assistant and bypass the Philips Hue hub altogether by running Zigbee2MQTT on my Home Assistant with a Sonoff Zigbee dongle plugged in. that helped solve random Hue Hub disconnects from my HA altogether. I highly recommend running all things zigbee this way.
I bought the Trådfri hub before I set up HA so it was easier to just connect it rather than resetting and reconfiguring everything. I've sorted it now, but if it comes to changing everything or staying again from scratch then I will cut out the middleman and have the devices talking directly to HA.