When you open IJ Scan Utility to scan, double check to make sure the printer is listed as TS3500 series network. If it is only listed as TS3500 series, click on the printer model and in the drop down, select the network option.
If the issue is not resolved, I recommend reaching out to Canon support for this issue. You will need to register your Canon gear HERE to access additional support options.
We look forward to hearing from you.