FTB Legend of the Eyes very laggy on decent system

[OliverB21]

Modpack

Other...

Modpack version

1.9.0

Has the pack been modified

No

Log Files

None

Describe the bug

First time using FTB, fresh install. Launch world and there are consistent lag spikes and FPS drops (200+ down to 15ish) every 10 seconds or so that last about 5 seconds. Followed various online guides (lowered all graphics settings to fast, reduced Mipmap to 0x, checked memory allocation (never above 70%), correct GPU is selected) with no luck

Steps to reproduce

1. Install FTB
2. Install modpack
3. Launch server
4. Create world
5. Lag begins

Expected behaviour

The game to run smoothly

Screenshots

None

Additional information

None

[OliverB21]

May be worth noting in the laucher, the loading bar is forever stuck on loading despite the game tself launching

[OliverB21]

Note 2 - Laucnhed a different modpack (FTB Unstable 1.21 1.0.1) and noticed the following differences:

After loading the bar at the top of the launcher states that the modpack "should be running! Enjoy" which was not the case with Legend of the Eyes, it remained in a loading state despite the instance of the game itself launching

The game ran smoothly, keeping a consistent, expect FPS level

let me know if there is any more tests I can do to assist diagnosing the issue