HTTP/404 On ConnectionRequest OR No Action!

we have some devices with brand TP-LINK within models like ‘TD-W8961ND’ or ‘TD-W8151N V3’
This devices return 404 on connectionRequests ! i don’t know why . we tried to fetch again ConnectionRequest info from device and again we got 404 on connectionRequest URL !

also we have a few devices with same brand and model : TD-W9960 v1 00000000 . this device return 200 on connectionRequests but will not initiate session with ACS even if plenty of time passed .

did you guys know how we should face this devices ? maybe we should ignore them and remove from inventory ?

What a massive reponses !
we had a MIDM device that intercept packets send to CPE and reset content headers .
i change the rule and keep content-type/content-length as same before and W9960 device starts working . ( Conten-Type should set as text/xml )

but we still have problem on connection request urls that return 404 .
can i set connection request url to cpe ? is it writable ?