https://www.politico.eu/article/investigation-ties-romanian-...
The Romanian National Liberal Party (opponents of Georgescu) bought the campaign. Their hashtag was "hijacked" (whatever that means) to boost Georgescu instead.
I do not know how TikTok works. Perhaps it is as simple as Georgescu supporters simply using the paid for hashtag for their own messages.
So, according to this article, the Russians did nothing. The Liberal Party engaged in questionable TikTok interference and Georgescu supporters jumped on the bandwagon.
The Western media falling silent on the issue would indicate that this politico.eu is correct.