Answer supplement
First of all, you have to make sure whether you have set it or not. It is in the "spatial data" of personal files. If the settings are confirmed, go to someone else's space to see if other displays are normal, nothing else can be displayed, or all of them are red crosses, then there must be something wrong with your mobile phone.
Answer supplement
Is your personalized signature text+picture? If the text can be displayed but the picture can't, it's a picture problem. If neither can be displayed, you can leave a message in the log. If you can see your signature in the log, it is a loophole in QQ space.