Not enough light

What's happening

Peperomia obtusifolia is a compact, mounding plant in good light, but in dim conditions it elongates its stems toward the nearest window, spacing the leaves far apart on weak, floppy growth. Variegated forms also fade toward plain green in low light, since the pale patches have little chlorophyll and the plant reverts to green to capture what light there is.

How to fix it

Move the plant to a brighter spot with plenty of bright, indirect light — a few feet back from an east or north window, or filtered south/west light works well. If your space is genuinely dim, a full-spectrum grow light makes a real difference and is often the only way to keep it compact through winter. Pinch the leggiest stems back to a leaf node to encourage bushier branching once the light improves.

This is general guidance based on common symptoms; individual plants vary.