What's driving up FPÖ support lately? Disappointment over the ÖVP? I noticed that they rebounded nationally as well, competing with the SPÖ for first place, even polling slightly ahead in most surveys.
In addition to the Russia issue, which was mentioned before, there's also the issue of immigration being way up again and COVID (which in hindsight mostly benefited incumbent governments) being completely forgotten already.
But I'd also say it's just a return to the standard level of support to which they always bounce back after an electoral setback - about 25%. Ibizagate has faded out of people's memory and was overshadowed by Kurz' scandal. ÖVP leader Nehammer is a party machine man, not a charismatic leader or a vote magnet for the Austrian right. And Kickl seems to be doing a solid job in uniting the party and picking a political line that resonates with many voters - not too moderate, not too extreme.