Horizontal Geometry Glitches on Reference Refresh

I have a horizontal layout for my merges and diverges, with dimensions per DMRB CD 122, as follows:

  • Nose taper using Ratio Offset Taper for length and nose ratio
  • Nose carriageway using Single Offset Entire Element for the carriageway width
  • Merge/diverge taper using Variable Offset Taper for the length and offsets
  • 1000m radius between the Merge/Diverge taper and the mainline carriageway edge using Arc Between Elements > Simple Arc for the mainline tie-in
  • 1000m radius between the Nose carriageway and Merge/Diverge taper elements to smooth the carriageway edge through the angle

I have found in several instances (3 out of 8 layouts in my current design), that no matter what I use for the final element, either using Arc Between Elements > Simple Arc or Arc Between Elements, or what order the elements have been selected as back and ahead, when the mainline reference is reloaded, or simply upon opening the model at the start of the day, the horizontal solution glitches, either giving the "Invalid Element. Uable to solve rule please correct element construction" error message or moving the acr to a different solution location.

The designed solution (north radius is 500m due to the mainline alignment in this situation):

Once refreshed:

The glitches can be resolved by selecting the complex and amneding the arc value to R1001m and then back to R1000m, or by dragging the arc midpoint grip, but I cannot find a way to prevent this glitch happening.

Does anyone have a similar experience and a way to prevent this happening?