Tasmota v12.x has dropped the homeassistant mqtt discovery in favor of their own. So discovery messages look like
tasmota/discovery/3494546279D8/config {"ip":"10.0.0.151","dn":"Fountain","fn":["Garden Fountain","",null,null,null,null,null,null],"hn":"garden-fountain","mac":"3494546279D8","md":"Generic","ty":0,"if":0,"ofln":"Offline","onln":"Online","state":["OFF","ON","TOGGLE","HOLD"],"sw":"12.0.2","t":"345picX","ft":"%prefix%/%topic%/","tp":["cmnd","stat","tele"],"rl":[1,2,0,0,0,0,0,0],"swc":[-1,-1,-1,-1,-1,-1,-1,-1],"swn":[null,null,null,null,null,null,null,null],"btn":[0,0,0,0,0,0,0,0],"so":{"4":0,"11":0,"13":0,"17":0,"20":0,"30":0,"68":0,"73":0,"82":0,"114":0,"117":0},"lk":1,"lt_st":1,"sho":[0,0,0,0],"sht":[[0,0,0],[0,0,0],[0,0,0],[0,0,0]],"ver":1}
instead of the old homeassistant/discovery
Iām thinking the easiest place would be to add this option in the mqtt binding but in homeassistant it looks like they went the route of creating a different plugin.
Erik.