unable to resolve column from last join in request-cluster-optimized mode

[aceforeverd]

      select                          
        account_no,         
        count(account_no) over w as cnt,
         -- check if there exists in window that right source agreement_no is null
         nvl2(nth_value_where(account_no, 1, isnull(agreement_no)) over w, 1, 0) as feat1,
         case when count_where(account_no, isnull(agreement_no)) over w > 0 then 1 else 0 end as feat2                 
      from (select account_no, 0 as agreement_no, cast(90000 as timestamp) as ts from request)                         
      window w as (     
         union (select t14.account_no, t16.agreement_nox as agreement_no, t14.ts from t14 last join t16 on t14.agreement_no = t16.agreement_nox)
         partition by account_no order by ts
         rows between unbounded preceding and current row
         exclude current_row instance_not_in_window
      )

unable to find .t14.col2

[aceforeverd]

A left TODO from #3205 (comment)

window ( union = multiple join )