Rule out simple causes
Check loose hinges, swollen wood, paint buildup, shifted strike plates, or localized framing issues. These are common and often easy to correct.
Look for a broader pattern
Foundation-related frame distortion is more plausible when multiple openings change, cracks appear at the corners of doors or windows, or floors nearby also feel uneven.
Track when it changes
If a door behaves differently during dry and wet seasons, note the timing. Seasonal movement can provide useful context about soil moisture and structural response.
Local context: Educational statements about expansive clay, wet/dry soil movement, and common warning signs are consistent with current guidance published for Sugar Land and the greater Houston area. They are general context, not a diagnosis for any individual property.