The status remained "awaiting for reviewer selection" after 5 months since re-submission
Contact someone else from the journal. This could be the editor-in-chief, the associate/managing editor if the journal has one, or simply the journal office. The journal is the only one who's able to solve your problem.

If the journal never replies regardless of who you contact, then you'll have to assume the journal is dead, withdraw your manuscript, and submit elsewhere.