Performance issues ever since Sacrifice update

[DessertArbiter]

Ever since the Sacrifice update I have been getting occasional FPS drops where the graphics quality also lowers for about 5 to 10 seconds before returning to normal. I have a 4k monitor but I run the game at 1080p with the highest in-game graphics settings and it used to run perfectly. I recently reinstalled Windows 10 but the the issue persists.

 

PC specs:

Operating System
            Windows 10 Education 64-bit
        CPU
            Intel Core i7 6700HQ @ 2.60GHz    48 °C
            Skylake 14nm Technology
        RAM
            16.0GB Dual-Channel Unknown @ 1064MHz (15-15-15-36)
        Motherboard
            HP 820D (U3E1)
        Graphics
            Generic PnP Monitor (3840x2160@60Hz)
            Intel HD Graphics 530 (HP)
            4095MB NVIDIA GeForce GTX 960M (HP)    42 °C
            ForceWare version: 398.36
            SLI Disabled
        Storage
            476GB NVMe Samsung SSD 950 SCSI Disk Device (Unknown)
            931GB Hitachi HGST HTS721010A9E630 (SATA)    25 °C