The bowl fills up significantly higher than usual immediately after a flush, but eventually subsides.
(for soap/grease/debris clogs)
Partial clogs are often caused by the "buildup" of materials rather than one single object. 7 Reasons Your Toilet Keeps Clogging - The Spruce partial clog toilet
Partial clogs can be caused by a variety of factors, including: The bowl fills up significantly higher than usual
You might not see water spilling over the rim, but your toilet will definitely "act up." Look for these indicators: partial clog toilet
(standard method)