Brokers often times mark your shares at a 0.00 purchase price prior to switch. The spread between the buy value (0.00) and the current price is the green. When the shares settle, the TITL purchase price will log and your unrealized gain will be accurate. IMO
This being the first symbol change I have been through I can only speculate based on what I saw with this one.
The old symbol didn't change so until zecco updates the shares in it's system to the new symbol it thinks nothing has changed in regards to the stock in question..... just a guess mind you.