I didn't have the issue until I was on foot looting a base and upon returning I found out I could not board my SRV, found out I was maxed on inventory,, so I dropped somethings and was able to get into the srv,, being that this was the 3rd base there was no canisters blocking my srv from being loaded onto the ship, I truly believe that I created a bug when I tried to get into the srv with 30 items in my pack and the srv was at 993/1000.
Next time this happens I will simply leave the SRV since all that inventory is already attached to me. meaning it seems I have 1000 slots, when I get out at a base and walk to the bar keep I can still access all those 1000 slots, even though I only have 30 slots on my suit, that 30 slots seems to only effect how much I can carry while on foot and picking up stuff. When I would click the inventory button outside the SRV,, then do the same thing outside the ship it showed all the same stuff with same counts. I believe the actual storage on the ship that holds canisters are separate from your on foot inventory.
Guessing this is a good thing now that I look at it,, if I had a bunch of stuff in my SRV and it got destroyed I would loose all that I had in it.