Version Info

• Minecraft, 1.21.1
• Item Collectors, 1.1.10

Description of the Bug
https://spark.lucko.me/GXczMsBWlr

Steps to Reproduce
install modpack allthemods 10
play

Screenshots
Unfortunately I can't give more details

Please provide some more info. Obviously just launching a modpack and playing in a world isn't going to cause peformance issues from item collectors.
The item collectors are blocks that you place on some sort of storage, so you likely have some setup with an item collector to pickup items which is causing lag.

The item collectors just try to insert item entities within their range into some sort of storage. This much lag from it ticking would imply you either have a very large amount of items entities or the storage's insertion is incredibly slow.

There is not much I can do about the storage insertion being slow as that would be up to whatever mod the storage is from.
If the problem is a large number of item entities laying around, I could limit the maximum number of items the collectors try to pick up every tick, however there is probably also something wrong with your setup if you get enough item entities for it to cause this much lag.

mob farm:

On the ground from the mod mob grinding utils spawn mobs, then they are driven into one pile by fans, where they die. A lot of loot falls from them, which is sucked in by the collector. Most likely, the problem is either in the huge amount of resources, or in the radius of the Advanced Item Collector.

To check whether the storage is just slow, you could place the item collector on some sort of other storage like a chest or something from another mod rather than the block the collector is currently on.

I have released Item Collectors v1.1.11 which limits the maximum number of items the collector tries to pick up and insert to 20 per tick.
If the update fixes your issue, then it was likely caused by a large number of items laying on the ground. If the update does not fix your issue, then it is likely caused by the storage you are inserting into just being slow.