Take your RH reader OFF the wet soil for one, make sure the reader gets the same airflow as the plants. That's deep below the level where the lowest RH will be. So, you aren't getting true readings imo.
Up your airflow and ventilate your grow room with fresh air. Make sure constant air flow throughout your tent and rotate and open up if you can any heavy flowers and keep a close eye
In a perfect setup you should have a 20L dehumidifier (with a compressor) and always run an exhaust on your tent with a negative seal.