It wont matter that your laptops IP has changed. The config in LB for the machines IP must match what the machine thinks.
I typically get the problem message if the machine is (1) ‘busy’ either i’ve paused a job (Hit Stop, ESC), it’s (2) truly busy (moving about and such) or the (3) machine is unreachable.
If it’s not 1, or 2. Then I would try to ping the laser from your laptop to ensure the IP that the laser knows is working for you. If you don’t get a ping reply I’d power cycle the laser and confirm the network settings on the laser. If everything looks right and you still cant connect/ping than I’d start looking at how your network is set up.