I got just rolled over by a Train and my Inventory space is back to base level size, if I invest one more point into the skill it increases by 10 slots (my setting) but nothing more.

Screenshots:
Skill level: https://i.imgur.com/6StiRmZ.png
Inv Size: https://i.imgur.com/VJaJRXF.png

just checkzing you sure it isn't related to the Armor you had on?
most armours also provide an inventory bonus

Edit: quick look says you may be onto something

i only have the very basic modular armor, that wouldn't explain such a difference.

I'm getting a similar problem, except I noticed it with reach distance. My reach distance resets after death and I can't seem to be able to do anything to get it back.

This is still happening for me, if I change armor, vanilla or otherwise, or die, I lose my inventory bonus, and I imagine the reach bonus as well (I have far reach, so I can't check in my current game)

happened to me just now when I died by train twice in quick succession, rather than the 8 previous roadkills. All bonuses are lost, and do not restore when some other bonus is purchased.

Happened again to me. It'd be great if we could reset the skills for one person (rebuying restores just fine) without having to reset everyone on the server.

I'm having the same issue, still. Wonder if there's a fix for this?

Same here. Lost inventory bonus after respawn in SE.
I have size 90 but should have 80 by default + 18*5 = 170!
https://imgur.com/a/Pr6Do7w

I have just tested here mods SE + RPG alone: nor dying or using jetpacks caused the inventory loss. Must be something else... another mod ???

Strange! My team mates on my multiplayer server can recover their bonus by dying multiple times. This is not working for me.