There is no difference from the trial except the time we provide to try LightBurn. No limits in the functionally what so ever, so this is not the issue. 
Burn what? What are your settings? What are you trying to burn? What firmware version are you using and what ‘Device’ profile did you select?
When posting, please provide as much information about what you have, how you have it configured, what you are trying to do, what your settings are, along with what you tried and what the results are. The details matter, more is better, as something said in a mention could give really good insight to those trying to help.