Local coordinate systems with combination factors can be tricky because the data often doesn't align with standard CRS definitions. The first step is always to verify where the data actually appears on a map.
A quick diagnostic approach: upload your shapefile to https://projectionfinder.comProjection Finder - it previews your data on a basemap so you can immediately see if it's appearing "too far north" or in the wrong location entirely.
If the visual location is way off from where you expect, the CRS definition is likely incorrect. For CAD data with local coordinates, sometimes you need to work with the surveyor or data provider to get the correct transformation parameters.
The visual verification step saves a lot of trial-and-error when dealing with non-standard coordinate systems.
