Your Roblox avatar might be blocky due to several reasons. One common cause is that Roblox sometimes fails to fetch your character appearance from the web APIs. When this happens, your avatar appears as a default blocky character. This issue is not related to the game itself and cannot be fixed by the developers.
Another reason could be the avatar type setting. If your avatar type is set to R6 instead of R15, it will appear blocky. You can change this setting in the game to fix the issue. Simply go to the game settings and switch your avatar type to R15.
There was also a bug where avatars were loading with default blocky arms instead of the chosen ones. Although this bug was fixed, it might occasionally reappear. If this happens, your avatar may look blocky.
Lastly, if your avatar is still not displaying correctly, you can try redrawing it. Go to the Avatar section and click the “Redraw” link. This process might take a few minutes but can help resolve the issue.