Imported my illustrator file in AE and all the vectors have this white block behind them. I did not convert them into shapes in AE neither did I use clipping masks in AI. Previous projects did not have this issue
I think it should be a file specific issue. Is your Illustrator document in CMYK color mode? Are there any blend modes being used? Feel free to share the Illustrator file here or via DM so that I can test.
Let me know. Moving this thread from Bugs to Discussions for troubleshooting.