@User I think this may be due to problem with the database unit

Do you mean in the GDS generation? Klaoyout can read the Magic GDS just fine.

Yeah, I've seen it before where the cells are in one database unit and the placement is on another. The net effect is that the cells are 5 times bigger than they should be

Wouldn't that affect both GDS? If they use the same cell library.

It would be interesting if you opened both layouts (correct and incorrect) and looked at file->layout statistics. See how they compare

The one with the fewer number of cells in Magic. Interestingly, under the reports folder, all I see for KLayout is XOR reports. Under Magic I see process reports. This suggests to me that the output of Openlane is Magic, and then something later in the process does a conversion to Klayout, along with an XOR of the final conversion. In other words, I think it is Openlane specific not OpenRoad per se.