Had a reply from T212 support…
The reason why you do not pay tax for both WHR and BBOX dividends is that they are both traded on LSE AIM which makes them locally traded. Therefore, no tax is applied in this case.
Struggling to find any info on what this “locally traded” stuff is all about though.
Not sure what a dividend payment/tax question affecting multiple shares and every user with those shares is doing being marked as account specific. Would appreciate if the above posts and this thread in general could be reinstated to public viewing so it can expand the general community knowledge of REIT taxation.