It would be helpful if your photos indicated the direction of belt travel.

Is there any skirting that can be install with reduced clearance that can trap material?

Is the material hard or lumps?

The more information that you can provide that better we can help you.

At what location does the carry side of the belt go around a pulley (typically at take-up pulley bends or a snub at least)? Has that pulley been checked for trapped material or build up?

Has the belt scraper belt check for trapped material? ■