Welcome to Android Central! What kind of phone are you using? Usually, screenshots are stored in Photos --> Screenshots folder. My Pixel 2 has everything sorted on the same page, but some phones may have side menus, maybe to the left hand side.
See if the issue persists in Safe Mode or after you restart your device. Maybe it's a glitch of some kind.
Welcome to Android Central! I believe @Morty2264 is referring to where you find the Screenshots folder in the Google Photos app. The actual directory (if you're using a file manager app) is /Pictures/Screenshots.
Welcome to the forums. Try this, open Google photos, open the side menu (hamburger icon top left or swipe right from the left edge), tap 'Device folders' and then select 'Screenshots'.