Wargaming interview questions

I sent the curriculum at Wargaming and they contacted me a few days later asking for a call with HR. The call turned out to not be the typical "HR screening" as it was presented, but was very much focused on skills and how I approach different projects (not too difficult). At the end of the call HR promised to be back by end of the next week with some feedback and then kept postponing the date because they had "a lot of candidates to screen". HR came back to me after more than a month after the initial interview asking if I was still available. This was already a red flag to me, anyway I agreed to have another call. On Monday we set up the time of the interview for the next day and in the evening HR asks me my salary expectations gross (please note that the JD posted did not contain any salary range or any other details about what the company would offer). In the morning the next day they cancelled the interview a couple of hours before it saying that they did not want to waste time of candidates that were not shortlisted (?). They could have just rejected me after the first interview and avoided to contact me to then cancel everything the day after. Unprofessional, non transparent, zero respect for other people's time.