Lack of lubrication

Friends, I have a problem. I have a Grand Voyager 3.3, but it seems the oil isn't reaching the valve lifters in the rear cover, causing a ticking noise, the typical ticking sound. The cover was opened up and was completely dry, with one rocker arm perforated and others notched. After that, the rocker arms and valve lifters were cleaned, all full of sludge. The oil pump was replaced, and the engine was cleaned with a fluid purchased at AutoZone that requires running the engine for 5 minutes. Afterward, a thinner 10W-40 oil was added. Initially, the noise stopped, but it returned. I'm not sure if there are any other options before taking the engine apart. I hope you can give me some suggestions on what I can do besides removing the engine, since, as you know, that's expensive. I would greatly appreciate any guidance. Have a good day. Bye.
PS The engine takes off perfectly and its speed is very good; it would be a shame to adjust it. Some people told me it could be the camshaft leaking pressure, but if that were the case, wouldn't it show up on the physical oil pressure gauge? Please, someone help me.

That will depend on where the coupling for the oil precion meter is, check the oil shock you want the problem is broken or obstructed.