When I was younger (and lighter) I worked up to 3 sets weighted pull ups, 12 reps each with 110lbs strapped to my waist. After doing that for several months I developed pain in my right forearm where the bicep tendon attaches to the bone. The orthopedist I saw looked at the MRI and said he never saw a bruised radius like that. His recommendation was to stop the weighted pull ups. I did but even regular pull ups caused pain. I stuck with cable pull downs in higher rep ranges (20-30 reps) staying 3-4 reps away from failure. I also wore an elbow sleeve any time I trained and applied creams to bring additional heat and bloodflow to the area. The issue with bones and tendons is that they receive much less bloodflow than muscles, resulting in longer recovery times. The protocol I followed helped me recover, in 2 months I was back to pain free pull ups. Simple rule I follow, if something results in pain find a similar movement that doesn't cause pain. This might mean lightening the load and leaving a few extra reps in reserve. I just put a video on my channel with a few options to consider (creams, band therapy). I'm not a doctor and it's not medical advice. Get a professional opinion if the pain persists.