I totally agree with the 20” bar recommendation. Not sure from the pics, but looks like a 24” bar on that 038. Drop back to a 20” or even an 18” and you’ll see a huge improvement.
I think way too often now days, saws get these long bars stuck on them when the extra length is not even needed, and the saw doesn’t have the proper HP to spin it. Just bogs em’ down.
Not to get off topic, but I’ve also noticed lately the marketing ploy in the big box stores, Lowe’s etc., of putting 20” and even 24” bars on these 455 Ranchers etc. which is way more bar than those saws have the ass for. But they ‘look’ impressive until the unassuming purchaser takes it home and buries it in an oak or hickory and the saw says waaaaaah Ugh!
Those size saws are much better suited for a 16” or 18” bar, with a maximum of 20” if cutting soft wood and you’re patient.