Checked Baggage Allowance on EI codeshare

Booked on BHX-DUB, one cash ticket and one Avios redemption both as BA codeshare. I'm finding it very difficult to ascertain the checked baggage allowance for either ticket. Cash ticket says 23kg in BA MMB whereas Avios says 20kg but both have an asterisk saying check with EI as allowances vary...........

EI site has no info at all as to what codeshare allowances are and putting the booking references into the EI site says there is no checked baggage allowance at all !!!!

Any thoughts or views ?