Cannot slew below horizon. Coordinate issue?

Description

I sometimes get an error indicating that slewing below the horizon is not permitted. I live in Vancouver Canada (49 degree, 20min N lat & 121 degrees, 39 min E long). When I use these coordinates I get the slew error. If I change the coordinates in my EQ6 to 121 degrees, 39 min WEST and then import the revised coordinates into SGP, then I can slew to the target but SGP then tells me that I am minus some number hours past the meridian flip, then constantly tries to execute the flip and fails. I do sometimes see the longitude represented at -121 degrees east, but I don’t know how to enter a negative value on the EQ6.

Not sure what to do here.

Aprox time of issue:

Link to Logs

Useful Info

OS: Microsoft Windows 11 Home
Ver: 3.1.0.558
.NET: 4.8