Make sure there isn’t a piece of plastic stuck to the heater under the bed - happened to me a couple times and it causes a very sudden high spot that manifests as a very thin spot on the first layer or a hole if it’s bad enough.
If your bed is PEI, I find that fresh from a dish soap wash or isopropyl wipe down isn’t always the best adhesion - but I find that printing just the first layer and then peeling and restarting can give an even better adhesion since the first layer picks up any contaminants very well, but that doesn’t seem likely to be the root cause here.
Are you able to watch up close while it prints the first layer? You should be able to see whether the plastic is still coming out of the nozzle when it hits the bad spot. You should also be able to easily see if the plastic is still coming out but balling up on the nozzle, or if it’s getting squished too much and having trouble due to a high spot, or if it stopped extruding for a moment and only pulled the last bit of extrusion into a thin hair while not pushing out any new filament even though there’s space under the nozzle. That will help narrow down the issue a lot between a bed leveling issue, adhesion issue, nozzle clog issue, or other extrusion issue.
Just looking at the picture, because it happens around the same spot as it goes back and forth, it feels more like something around that spot on the bed - either a high spot or a dirty spot. But watching what happens up close and how the filament coming out up close behaves should help determine.
Just tossing some more ideas in the ring:
Make sure there isn’t a piece of plastic stuck to the heater under the bed - happened to me a couple times and it causes a very sudden high spot that manifests as a very thin spot on the first layer or a hole if it’s bad enough.
If your bed is PEI, I find that fresh from a dish soap wash or isopropyl wipe down isn’t always the best adhesion - but I find that printing just the first layer and then peeling and restarting can give an even better adhesion since the first layer picks up any contaminants very well, but that doesn’t seem likely to be the root cause here.
Are you able to watch up close while it prints the first layer? You should be able to see whether the plastic is still coming out of the nozzle when it hits the bad spot. You should also be able to easily see if the plastic is still coming out but balling up on the nozzle, or if it’s getting squished too much and having trouble due to a high spot, or if it stopped extruding for a moment and only pulled the last bit of extrusion into a thin hair while not pushing out any new filament even though there’s space under the nozzle. That will help narrow down the issue a lot between a bed leveling issue, adhesion issue, nozzle clog issue, or other extrusion issue.
Just looking at the picture, because it happens around the same spot as it goes back and forth, it feels more like something around that spot on the bed - either a high spot or a dirty spot. But watching what happens up close and how the filament coming out up close behaves should help determine.