Known issueHow-toUpdated · 3 replies on Steam
Where Do I Find the Early Loftian T-shirt?
Short answer
Suggested fix (unconfirmed): Go to your housing island to trigger the reward banner, then check the bottom of the tops section in your character customization menu.
The problem
It shows redeemed on the website but when I logged in and linked my email I could not find it in my clothing section. :(
Did this work for you?
Source: original Steam Community discussion. Quotes are shortened; all credit goes to the posters.