The LP file format is designed to be human-readable. Gurobi writes coefficients in LP files with fewer decimal digits. Also, the LP file format does not necessarily preserve the ordering of variables. As a result, when you export a model to the LP format, read the LP file, then optimize it, the solution path may be different. Thus, the LP format is best used to visually inspect a model for correctness.
Gurobi writes MPS files with full precision in a manner that maintains variable order. Thus, the MPS format should be used when you want to ensure that Gurobi reads the exact same model that was exported.
Deriving MPS/REW files when needed
When an MPS/REW file is required, write it directly from the original model built through a Gurobi API (e.g. Gurobipy). Do not read a previously exported LP file and then write it as MPS or REW, since any loss of numerical precision or variable ordering caused by the LP export cannot be recovered this way.