[4] Gaining addition racing experience after the European Junior Championships and before the 2018 Summer Youth Olympics, Markov competed at the 2018 Swimming World Cup stop in Kazan at the Palace of Water Sports and conducted in long course metres.

In the prelims heats of the 50 metre freestyle, Markov qualified for the final ranking eighth with a time of 23.10 seconds.

[11] Day three of competition, Markov ranked first in the semifinals of the 50 metre freestyle with a time of 22.30 seconds and qualified for the final.

[11] On 4 July 2019, at the 2019 World University Games conducted at Piscina Felice Scandone in Naples, Italy, Markov ranked sixth in the semifinals of the 50 metre butterfly with a time of 23.78 seconds, qualifying for the final the next day.

[24] At the Tollcross International Swimming Centre in Glasgow, Scotland on 4 December for the 2019 European Short Course Swimming Championships, Markov swum the second leg of the 4×50 metre freestyle relay in a time of 21.36 seconds in the prelims heats, helping advance the relay to the final of the event ranking first at 1:25.07.

[26] On the first day of the 2021 Swimming World Cup stop in Kazan, 28 October, Markov qualified for the final of the 50 metre freestyle ranked sixth with a time of 21.51 seconds from the prelims heats.

[28] The next day, Markov swam a personal best time of 47.18 seconds in the prelims heats of the 100 metre freestyle, advancing to the final of the event ranked sixth.

[37] Markov was one of the athletes named to the Russia national team for the 2021 World Short Course Championships in Abu Dhabi, United Arab Emirates in December.

[46] Day three of competition, he ranked 14th in the prelims heats of the 50 metre freestyle with a time of 21.50 seconds, qualifying for the semifinals in the evening.

[47] In the semifinals in the evening, he swam a personal best time of 21.33 seconds, ranked tenth overall, and did not advance to the final of the event.

[51][52] Fighting to keep his national competition career alive, Markov competed at the 2022 Russian Championships held in April at the Palace of Water Sports in Kazan, setting a new personal best time of 21.94 seconds in the long course 50 metre freestyle.

[3][61] Earlier in the day, he ranked eleventh in the preliminaries of the 50 metre butterfly with a 24.09 before withdrawing from competing in the evening semifinals.