I had this happen as well with my SR22. Here is a thread I started...
I updated it with info on what I found as the problem.
When you get a chance, look in the barrel... ensuring first the gun is clear and preferably disassembled... you will probably notice lots of leading and fouling in the barrel. Even a dirty barrel looks smooth... lead fouling looks rough.
Before you shoot again check the barrel and clean it well...
Lead fouling will get worse, and shooting more rounds will not fix it only worsen it.
Long story short... Plain lead bullets fouled the barrel... Use plated bullets... Bullets that have a thin plating of copper or brass. The Winchester M-22 are plated but look black, its treated copper that has a black color... other plated bullets have the typical copper color.
Other plated bullets that are still cheaper...
Remington Golden Bullets
I find the Federal and Winchester bulk to be hit and miss on reliability. Due to softer lead and poor crimping of the case which allows the bullet to wobble or feel loose in the case.
The Golden bullets have treated me better so far. A little loose of crimp but not as bad.
The Winchester M-22 ammo is very high quality and has been 100% reliable for me so far. No looseness and round nose so feeding is good.
The M-22 costs a little more, but I feel it is worth a few extra bucks for a 500rd box... about $22
Other bulk runs $16-20 per 500rd box.
CCI Mini Mags are almost a sure bet for reliability, but $6-7 per 100.
The M22 ammo I mentioned is loaded to similar power levels.
Ammo rated for around 1200fps with 36-40gn bullets, tends to work very well in semi-autos. So look on the box and see if it has the velocity... If not, ammo in that range tends to be labeled "high velocity".
Standard velocity is around 1000fps... Hyper velocity is over 1400fps.
The SR22 can handle the Hyper velocity ammo very well.