Elevation viewports and level markers shifting position on sheets after Mirror Plan solve (LotSpec + Revit 2026)

I’m running into an issue where elevation viewports and level markers move position on sheets after running a Mirror Plan solve in LotSpec. The sheets are correctly laid out before the solve, but once the mirrored option resolves, the elevation viewports and their associated level markers shift — they don’t stay anchored where they were placed.

Setup:

  • Revit 2026 + LotSpec (Simpson Strong-Tie plugin)
  • Option-rigged model using LotSpec’s option-solving/Mirror Plan mechanics
  • Sheets contain elevation views with viewports placed at specific positions, plus level markers

What I’ve tried so far:

  • Compared against a reference project that doesn’t exhibit the issue, to isolate what’s different in setup
  • Currently testing two hypotheses:
    1. Scope box behavior during the mirror operation (rotation/position not resolving symmetrically)
    2. Model group structure interacting badly with the mirror solve

Questions for the community:

  1. Has anyone else seen viewport/level marker drift specifically tied to Mirror Plan solves in LotSpec?
  2. Is there a known interaction between scope box mirroring and elevation crop region/viewport position that would explain this?
  3. Does model group structure (nested groups, group origin placement) affect how mirrored elevations resolve on sheets?
  4. Is there a “correct” way to set up scope boxes/elevation views specifically to survive a mirror solve, that isn’t documented in the standard LotSpec onboarding materials?

Any insight — even “here’s what NOT to do” — would help. Happy to share more details on model setup if useful.