sql - UPDATE query vs. Table FILTER yields different rows count (MS ACCESS) -

i have problem count of updated rows through update query.

when run update query:

update t002vyk  inner join tzemnyplyn on t002vyk.bmsid = tzemnyplyn.[id budovy]  set t002vyk.iszemnyplynhistoricky = yes; 

it says, 2916 rows updated.

i run update query. (i tried different queries well, same results).

when filter table t002vyk on field iszemnyplynhistoricky = yes, 2701 rows.

just provide info, here design view of field iszemnyplynhistoricky:

(i tried using number data type, 0/1 values, no luck)

my questions
why different results in filtered table, in update query? how solve problem?

solution:
in tzemnyplyn table, there duplicate id's [id budovy], counted more once time in update query results.
after creating unique list of [id budovy] update query showed 2701 rows table did.

thanks tim biegeleisen's comment, getting me on track.