You cannot usually just download an old RPH from the main site. You must either have backed up your files or use the built-in rollback feature of RPH. 1. Utilizing the RPH Rollback Feature
As GTA V evolved and integrated more complex systems for GTA Online, the base game's hardware demands slightly increased. Players running GTA V on older or budget-friendly PC hardware occasionally find that older iterations of the game—and consequently, older versions of RPH and LSPDFR—run with significantly better frame rates and fewer memory leaks. The Challenges of Sourcing Legacy Builds