I also did that. Will not connect. Which is odd that I can get it to connect using the GBRL settings. The Marlin settings will not connect. So Then I used inline, marling settings and put gcode on sd. Still same problem. Will not keep the laser on. Changed settings to us M03 and M05. Still same problem. Here is the Marling gcode from lightburn
; LightBurn 1.1.03
; Marlin device profile, absolute coords
; Bounds: X20.27 Y51.36 to X84.75 Y69.56
G21
G90
; Cut @ 3050 mm/min, 100% power
M9
M05
G0 X23.975 Y51.441 F0
; Layer C00
M03 S255
G1 X24.348 Y51.393 F3050
G1 X24.723 Y51.365
G1 X25.098
G1 X25.474
G1 X26.008 Y51.413
G1 X26.534 Y51.51
G1 X27.049 Y51.656
G1 X27.548 Y51.852
G1 X27.959 Y52.063
G1 X28.338 Y52.318
G1 X28.684 Y52.613
G1 X28.993 Y52.944
G1 X29.263 Y53.308
G1 X29.491 Y53.701
G1 X29.673 Y54.121
G1 X29.808 Y54.563
G1 X29.953 Y55.254
G1 X30.052 Y55.952
G1 X30.106 Y56.656
G1 Y57.362
G1 Y69.557
G1 X27.745
G1 Y57.228
G1 Y56.711
G1 X27.715 Y56.196
G1 X27.653 Y55.684
G1 X27.558 Y55.176
G1 X27.481 Y54.931
G1 X27.376 Y54.699
G1 X27.246 Y54.482
G1 X27.091 Y54.283
G1 X26.915 Y54.103
G1 X26.719 Y53.944
G1 X26.503 Y53.808
G1 X26.271 Y53.698
G1 X25.995 Y53.6
G1 X25.712 Y53.528
G1 X25.425 Y53.483
G1 X25.136 Y53.465
G1 X24.847
G1 X24.559 Y53.508
G1 X24.274 Y53.569
G1 X23.994 Y53.657
G1 X23.78 Y53.755
G1 X23.579 Y53.876
G1 X23.394 Y54.017
G1 X23.225 Y54.176
G1 X23.075 Y54.354
G1 X22.945 Y54.547
G1 X22.837 Y54.754
G1 X22.751 Y54.974
G1 X22.609 Y55.478
G1 X22.505 Y55.991
G1 X22.438 Y56.509
G1 X22.411 Y57.032
G1 X20.274 Y56.739
G1 Y56.147
G1 X20.322 Y55.557
G1 X20.414 Y54.972
G1 X20.55 Y54.396
G1 X20.75 Y53.829
G1 X21.03 Y53.301
G1 X21.384 Y52.82
G1 X21.807 Y52.394
G1 X22.296 Y52.045
G1 X22.825 Y51.768
G1 X23.388 Y51.565
G1 X23.975 Y51.441
M05
G0 X35.484 Y54.306 F0
M03 S255
G1 X35.367 Y54.618 F3050
G1 X35.306 Y54.945
G1 Y55.28
G1 X35.356 Y55.615
G1 X35.473 Y55.943
G1 X35.71 Y56.317
G1 X36.019 Y56.627
G1 X36.388 Y56.864
G1 X36.803 Y57.017
G1 X37.339 Y57.151
G1 X37.878 Y57.263
G1 X38.422 Y57.355
G1 X38.969 Y57.425
G1 X39.511 Y57.518
G1 X40.14 Y57.634
G1 X40.761 Y57.781
G1 X41.374 Y57.959
G1 X41.978 Y58.168
G1 X41.992 Y57.646
G1 Y57.125