A quick search found these threads:
- MMPBSA_Error Could not import PyQt5/PyQt6 · Issue #272 · Valdes-Tresanco-MS/gmx_MMPBSA · GitHub
- [Question]: Could not import PyQt5/PyQt6 · Issue #208 · Valdes-Tresanco-MS/gmx_MMPBSA · GitHub
- gmx_MMPBSA_ana error: Could not import PyQt5 · Issue #176 · Valdes-Tresanco-MS/gmx_MMPBSA · GitHub
- Could not import PyQt5 but the package is in conda list · Issue #100 · Valdes-Tresanco-MS/gmx_MMPBSA · GitHub
Perhaps one of them can be of use for you.