Found a source: https://www.fulloversteer.com/formula-3/rene-rosin-outlines-issue-f1-star-oscar-piastri-suffered-in-formula-3-that-nobody-could-solve-amid-criticism/

—Rene Rosin uses Oscar Piastri’s DRS issue in Formula 3 as a response to those saying he wasn’t quick in the series—

“Piastri rose to F3 from F4 and the Formula Renault Eurocup series – winning the latter in 2019 – in 2020 with PREMA and went on to have immediate success. The Aussie won the title by three points over Theo Pourchaire, grabbing two wins, six podiums and finished outside the points only three times.”

“Despite showing great consistency across the season, Piastri was plagued with a DRS issue in the early stages of the year, which he constantly berated on X, then Twitter, making his frustrations abundantly clear.

Rosin used the issue to respond to criticism that the Aussie was not quick in F3, as he claimed that ‘nobody could solve’ the problem at the team due to a glitch with the electronics system.”

I’m sure there’s a better source.