No data returned with subquery

the following query results data:
SELECT * from (select last(“WEZ1001.MW01”) FROM “f8f23fb2-39c5-4db6-b9a6-360674eebf64”
WHERE time >= ‘2020-01-06 23:00:00’ and time <= ‘2020-01-07 01:00:00’ GROUP BY time(15m)
fill(linear))

returned dataset:
Time f8f23fb2-39c5-4db6-b9a6-360674eebf64.last
2020-01-07 00:00:0 2789827
2020-01-07 00:15:00 2789869
2020-01-07 00:30:00 2789910
2020-01-07 00:45:00 2789951
2020-01-07 01:00:00 2789991
2020-01-07 01:15:00 2790032
2020-01-07 01:30:00 2790072
2020-01-07 01:45:00 2790113
2020-01-07 02:00:00

but when I change the query and add a where clause to this subquery for a specific time it returns no data:
SELECT * from (select last(“WEZ1001.MW01”) FROM “f8f23fb2-39c5-4db6-b9a6-360674eebf64”
WHERE time >= ‘2020-01-06 23:00:00’ and time <= ‘2020-01-07 01:00:00’ GROUP BY time(15m)
fill(linear)) where time = ‘2020-01-07 00:00:00’

why is this??

you have to select a time span of 15m at the first where clause

hi melrose, thank you - this works! but its not clear to me why… there is a result at 2020-01-07 00:00:00 from the subquery. why can’t I select it with = ‘2020-01-07 00:00:00’?

you cant have twice a where