Cannot pick up tossed spyglass from the ground in the skybox

[RedstoneDubstep]

While playing Fetchr with bl4ckscor3, I tossed the spyglass from my offhand on the ground in the skybox, but I was unable to pick it back up again, rendering me spyglassless. I tried this with several spyglasses that I gave myself using /give, and I could pick up none of them, and neither could bl4ck in the same skybox. I also noticed through /data get that these spyglass item entities had a pick-up delay of 32767s.

bl4ck himself did not experience this bug however, as most of the time he could not even toss his spyglass. Either the spyglass had a pick-up delay of 0, or the tossed spyglass was deleted and he was immediately given a new one through /give.

So I'm assuming this is a multiplayer-only bug.

[NeunEinser]

If you give yourself a spyglass manually, it should be /give @s minecraft:spyglass[minecraft:custom_data={ fetchr: { skybox_spyglass: true }}]. Without the custom data, it will behave like any other item like you are describing.

[NeunEinser]

Was the server lagging when you were dropping the original spyglass? One issue that's imaginable is that you get more than 5 blocks away from the spyglass after dropping it within the same tick you have dropped it. If that's the issue I can simply increase the radius.

Well, I am not actually sure this would necessarily do it, if you are that far away already, you probably wouldn't be able to pick it up anymore anyways, and it might become subject to being frozen like other items in the skybox phase anyways.

If you play on a server again, can you do more testing and figure out when exactly this happens? Looking at the function, I don't see why it wouldn't work for multiplayer in general, it is executing correctly for every player in the skybox, and it was also working on slicedlime's stream with multiple people.

[RedstoneDubstep]

We did some more testing, and it turns out this is also reproducible in singleplayer. It works on any spyglass that has the fetchr.skybox_spyglass tag (even ones you give yourself using /give).
If you press Q once holding one such spyglass, it immediately gets picked up again, as expected. However, if you're holding Q (which at least on Windows results in the key being spammed after some time), the spyglass is repeatedly picked up immediately until it's not anymore, and after that it's lying on the ground indefinitely (having that insanely high pickup delay).
I as the player am not moving during this bug reproduction. I didn't test whether lag influences this, though it's fairly easily reproducible after pre-gen is done, so I'm assuming lag isn't a big factor.