what are you busy about these days?(这句话有语法错误么?)

be busy with sth
be busy doing sth
忙于某事.
两者意思一样.

感觉别扭，没人这么说。
一般会说 what are you busy doing these days

应该用with,而不是about.
be busy with忙于做某事.
What are you busy with these days?