They are in the same family "Ursidae ", which contains only 2 genus' as far as I can determine: Ursus and Ailuropoda. Like much of zoology, the family-genus-species differentiations are far from perfect. A quick search in my encyclopedias, and on-line, and every refrence I see classifies Pandas as bears. The burden of proof is on you to prove otherwise. PS - gainsaying is not proof.
Just did a quick read through the way the name "panda" came up and given that NO Chinese biological classification system has ever, ever used anything like the word "panda" for these animals, it can fairly be argued that the word was derived from that of the common name of a "Chinese Fast Food" restaurant chain, Panda Express!
Genera and families are distinctions of convenience although we are working toward genetic distance.
A species is distinct from another if they do not interbreed in the wild.
Contrary to popular belief on these threads there’s no on/off switch for speciation, it’s a process involving diminishing fertility and/or breeding opportunities.
As for “they’re in the same family”, as I asked upthread, is a rose a pear (or vice versa)?