Oof, 213fps with 0.25g is just 0.52J, under half the power you should be getting. If that's a stock spring, your air seal is... well, not sealed. You're not likely to solve that with a barrel and hop.
There's something quick you can try, which is to open it up and put silicone oil or spray into the nozzle. Give it a swirl around and some time to soak into the piston and cylinder head rings, then give it an auto burst before re-assembling to get most of it out. While it's apart, take the barrel out of the hop unit and check the rubber for signs of damage or perishing. If it's stiff, give it a lube with silicone oil then a thorough clean out. When you put the barrel back in, be sure that it's pushed all the way back into the hop unit, and that the clip is properly engaged.
After doing that, if it's still under-powered, I'd suggest opening the gearbox up and lubing or if necessary replacing the piston ring.
If you want to dive ahead and change the barrel and hop rubber then I'd suggest a ZCI 6.02mm or AOLS 6.01mm, and a Maple Leaf hop rubber, and a omega nub clone from https://www.ak2m4.co.uk/
But that won't cure your air seal issues, unless it's just down to a perished hop rubber or mis-seated barrel.