What does it mean for a single ordinary woman to be surrounded by a man who hasn't known her for a long time and only sends her blank messages from time to time?

If you think it's okay: then this person has a problem with his mobile phone or the network, and people don't know. You can remind him warmly that there is something wrong with your mobile phone. Do you want to see it? I often receive your blank messages. You'd better check it, or there will be extra expenses you don't know about every month ~ ~

If you want something, you can also send him a blank message from time to time to see his reaction.