If Garcia wins by around 9.5% which is likely, then in the 6 congressional special elections that have occurred since the 2018 midterms, Republicans have outperformed Trump by 1.5% on average, in the 8 congressional special elections that occurred between 2016-2018, Republican ran 10.6% behind Trump on average, so since the midterms in congressional special elections, Republicans have been doing 12.1% better than they were in 2016-18 and are running even with Trump on average.
A lot of the 2016-2018 races were special though due to the incumbent messing up so that could be why for a few.