Gurobi lost solution #561

I have a pretty simple lp-model.
problem.zip
If you run it with the command
minizinc --solver gurobi --allow-multiple-assignments --output-mode json --output-time --output-objective --output-output-item -s -p 8 -O 1 --time-limit 10800000 --solver-statistics -i solver_mip.mzn mzn_data4vrw1dts.json > log_gurobi_fzn.log
then there will be no solution in the log:
%%%mzn-stat: nSolutions=0
but
%%%mzn-stat: objective=0.934210526316

Is it problem of mininzinc or gurobi?

If it is problem of gurobi can you help to create issue for them?