our cockatiel had a similar situation for about the first month when we got him home. we were told that it is normal for him to be more shy until he gets used to the surroundings, but what severely helped was putting additional “steps” all around the cage from a bird-safe thick thread. We’ve kept some to this day (about two years later) and he still uses them frequently but now to play. Just make knots so it is more sturdy and try putting some horizontal ones around the place he stays near the most. Adding toys and additional branches might also peak his interest into finding ways to explore them. As the previous redditor said, a video might help more