I did the upgrade to 1.5 yesterday and for what I was working on yesterday I had no issues. This morning I needed to run a test on some new material so I setup my usual test of fixed settings and only varying the pass counts. This allows me to make sure the material works well as well as lets me judge how many passes gets me how deep.
It got thru the first 5 just fine, but when it hit #6 (300 passes) it drops power significantly to the point where it is more like a cleaning pass. I thought maybe it had just skipped straight to the cleaning pass I have set for each one, but it just kept repeating passes like it was trying to deep engrave.
I restarted lightburn and opened the file again and just selected the last 4 that needed to be done and continued and now #6 (300 passes) worked as expected as did #7.
Then on to #8 (400 passes) it again does the same thing.
That is what it looks like after doing maybe 75 passes or so.
Close and reopened lightburn and it is now doing number 8 correctly.
So I am not sure what is going on but each layer has its deep engrave and then a cleaning pass at the end.
Hopefully this is a bug you can reproduce and fix.
Thanks.