if i disable bobby, the lag spikes go away. but if i enable bobby, there are big lag spikes (fps drops) whenever i move through a chunk border.
i tried to upload a screenshot, but it doesnt upload :(

I'll need more than that. Mods, versions, hardware, etc.
Cannot reproduce.

I've had the same problem, adding starlight seemed to have mostly fixed it, substantially increasing minimum fps . But as you know, starlight doesn't play well with bobby.

I'm running minecraft 1.17.1 on java 16
PC specs:
Intel i7 8700K @5ghz
32GB RAM @3200mhz CL18 (4GB allocated to MC)
GTX 1080Ti @2025MHz

Here is a list of the mods I'm using

Without Starlight:

With Starlight:

Another thing that helped was installing my MC client and subsequently bobby's files on a ram disk. (About doubling minimum framerates)

So my guess is is that it is a combination of high access latency and vanilla's super inefficient chunk building system not playing nicely on certain hardware/mod configurations.
Hope this helps :)

I think it's a vanilla bug.
https://bugs.mojang.com/browse/MC-162253

The reason you don't get this problem after installing StarLight is because StarLight fixes this problem.

I don't think it is, because I don't have this issue in vanilla at all.

You need to set the server view distance and client view distance to the same value as the view distance set in bobby and test it.

Closing as likely vanilla bug which is just more noticeable with Bobby because it loads more chunks.
Also, Bobby now works with Starlight, so there's a good fix for it.