Old sounds returned after the maintenance
As part of today's maintenance of major PlayerUnknown's Battlegrounds servers, developers have taken into account community feedback and rolled back 4.3 patch changes related to step sounds. Information about this was published in the official Twitter of PUBG support service:
PC Players: Live server maintenance is now complete.— PUBG Support (@PUBG_Support) October 2, 2019
Due to player feedback, we've reverted footstep sound changes implemented in Update 4.3.
We plan to make additional changes in the future and will share further details at a later date.