It goes without saying, but Robert Tonyan has certainly come a long way since entering the NFL as an undrafted rookie in 2017 and being a college receiver, no less. Not only was Tonyan transitioning to a new position, but to a very difficult one at that.
Tight ends have to be able to run routes and understand passing concepts like a receiver, but also have proper blocking technique like a tackle--this is a big reason why we see so many young tight ends get off to slow starts in their NFL careers.
So naturally, when Tonyan had just 14 combined receptions during the 2018 and 2019 seasons, that should have been expected as he was still developing into his role.