There is no End of Support date for 3.4.1.38 yet. Netwrix provides support for two GA versions, so for PingCastle it will be 3.3 and 3.4. Since 3.4.1.38 is a patch within the 3.4 stream, it follows the same support lifecycle as 3.4 and remains supported until 3.4 itself reaches End of Support.