PDN: faulty pad connections

[mole99]

Describe the bug

Something strange is going on with the pad connections in this example design:

For some reason, some of the Metal2 pad connections extend into the core area.

This is related to the PDN grid for the SRAM macros. If I disable this grid, then the Metal2 pad connections are correct:

However, there seems to be yet another issue, as there are a few Metal4 stripes which extend to the pads.

This should not be the case for two reasons:

1. The pads don't have pins there on Metal4.
2. I restricted the layers via -connect_to_pad_layers Metal2

I would appreciate it if someone could take a look at this.

Expected Behavior

The Metal2 pad connections should not extend into the core area.
The Metal4 stripes should not extend to the pads.

Environment

Recent OpenROAD

To Reproduce

reproducible.zip

Simply run ./run.sh

Relevant log output

Screenshots

No response

Additional Context

No response

[mole99]

It seems that using Metal4/Metal3 for the core ring works around the issue, but I would really like to use Metal5/Metal4 for it since Metal5 is much thicker :)
See: https://gf180mcu-pdk.readthedocs.io/en/latest/analog/layout/inter_specs/inter_specs_3_43.html