Octoprint ignores Z-Offset, nozzle starts too low at random heights

I may be confused but unless you have gcode defined in OctoPrint's
GCODE Scripts Before and After print job, OctoPrint should just be sending the gcode from the file being printed without modification.

It sounds to me like there may be some absolute (G90) / relative (G91) issues. G28 should set the printers coordinate base, the Z-offset should be defined in the "firmware" (i.e. the EEPROM). If it isn't stored in the EEPROM, then the appropriate M851 command should be inserted where needed.

I have the exact same issue, just did a fresh install of octoprint, have not changed much, ender3 v2, prints perfectly off the SD card, but if i try to print via the web interface the nozzle prints really high as if ignoring my Z offset of -1.35. also there is no display of an ongoing print on my printers LCD display, it stays on the default home page like when the printer is idle. I am using BL touch.

The Ender 5 Plus (and I think the CR10-S and CR-X) have a screen that stores Z-offset code in a menu that can only be reached during a print. Could this have anything to do with it? The Z offset being set on the printer affects the Z offset value, but maybe OctoPrint doesn't invoke it.