3.3V TTL is dropping to 2v when connected to pin
3.3V LVTTL logic only guarantees a high of 2.4V (Voh) at its rated current. What is the load? If it’s too much for your device you may need to add a buffer. If it needs to be a ‘true’ 3.3V, then it needs to be a FET buffer which can swing all the way to the positive rail.