System Information
Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 418.91
Blender Version
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-05 06:13, hash: rB66684bdff30f
Worked: In a 2.8 version from 2 to 3 weeks ago, don't know the exact one. Definitely in 2.79.
Short description of error
When using the Grid Fill command, you can't adjust the Span and Offset values independently in the Last Operator panel. Span can't be changed, and Offset affects Span.
You used to be able to use Span to choose between the minimum and maximum amount of polygons you could fill a hole with, and Offset to choose their orientation, which was very useful.
Exact steps for others to reproduce the error
Use this file, select the edgeloop of the hole and use Grid Fill, and if you use one of the last Blender version where this worked differently, compare the two.