Timezone issue with abbrevs and Daylight Savings


it seems there is an issue with timezone conversion, when using abbrevs (eg CET)
I’m using CONVERT_TIMEZONE function (Dremio).
According to system table sys.timezone_abbrevs, CEST is indicated with flag is_daylight_savings to true.
However when I run
select CONVERT_TIMEZONE(‘UTC’,‘CEST’, ‘2021-08-03 07:00:00’), CONVERT_TIMEZONE(‘UTC’,‘CEST’, ‘2021-12-03 07:00:00’)

(one in summer, the other in winter), I would expect not getting same hour, but I obtain same hour in result : 2021-08-03 09:00:00.000 and 2021-12-03 09:00:00.000
is it expected ? i also tried with CET and I’m getting 2021-08-03 08:00:00.000 and 2021-12-03 08:00:00.000

CET is not supposed to have a constant offset with UTC, it is supposed to change with Daylight saving time
Central European Time - exact time now - Time.is.

however when I run
CONVERT_TIMEZONE(‘UTC’,‘Europe/Paris’, ‘2021-08-03 07:00:00’), CONVERT_TIMEZONE(‘UTC’,‘Europe/Paris’, ‘2021-12-03 07:00:00’)

I get correct results:
‘2021-08-03 09:00:00.000’ and ‘2021-12-03 08:00:00.000’ (resp Summer and Winter time)

Am I missing something ?