I have had issues as well. After doing some research and lurking on another site for farming only, I have changed my chemical program including equipment.
This is what I do-
Use clean water. I have community water that has sediment (sand) that can clog small tips. I use a screened hose washer that seems to help. May have to use a small screen to strain water, so far not needed. T prevent foaming, the inlet line goes to the bottom of the tank.
Mix chemicals according to label!!! Most require at least 1/2 of water before adding chemicals. Last half of water added slowly as tank is thoroughly mixed by bypass valve.
If multiple chemicals are used, mixing order is crucial as some will clump up and plug everything unless mixed in correct order.
Use a pump that is Roundup resistant, cheap pumps will corrode from glysophate and chunks will break off. The pump I use came from Shoup for $350. A good pump and bypass makes the system work to spray correct pressure, crucial to appling correct amount of chemical. Some stuff is pricey as well as dangerous, I only spray what the label says as far as amount per acre.
I use about a cup of Dawn in each 150 gal load to help in cleaning the lines and tips from atrazine, 24D, etc. It also keeps gunk from sticking to lines, valves, elbows, etc. Cheap stuff works but Dawn is the best.
I always clean the filter. I have rebuilt my system several times, what works best is filter after pump just before the manifold to catch any pump parts. I may add more filters before the tips.
I use a Sprayer Rinse ball mounted at the top of the tank that a hose can connect to for rinsing with clean water. After about 25 gal has gone through the ball, a hose from the pressure line connects to the ball to second rinse. This is usually 50 gals of clean water with tank cleaner that is ran through the pump and rinse ball before running through all the tips. This is when any tip that has issues will be evident. If a tip burps once, it may clog next time.
I have a broadcast nozzle, 4 row drop, 3in wiper and a 12 ft bar with overlapping tips. I use the broadcast nozzle for burndown and spraying when crop (Corn) is small prior to spreading N. After applying granular Urea (N), I will spray Roundup/Atrazine through the drops when the corn is almost too tall to get the tractor over without damaging the plants. Once that is done, I cant get back in the field with a tractor. I have 2 shots to get rid of grass and weeds if the crop is going to make. I used the wipe pipe to deal with a resistant Pigweed problem (Gramoxene, bad stuff!)
Every step is crucial to make my herbicide program work. Anytime there is a issue, I usually find the problem is something I did or did not do correctly.
Hope this helps, nothing worse than having issues that don't seem to get better with time.
Good Luck!