It's your fault for not being careful.
...right. I should've anticipated that this game allowed for further shoving than what I am used to in D&D 5e. 5 feet and 5 meters are almost the same, anyway. (Big sarcasm here.)
You say Iwasn't careful, but I have been. I have explored the whole goblin camp before making a move. The "goblin holes that allow them to climb 50 meters instantly" are invisible. So if you could block them, you had to know they were there. Big d*ck move to pin it on my inaptitude when you know about it beforehand.
But let's assume that ALL that I said previously was normal and preventable. Just now, a goblin tossed a vial of acid from a distance of 30 meters straight on my party. That 100 feet. In D&D, 5e, you can't throw ANYTHING with your hand past 60 feet. You're going to tell me Ishould've been careful? That it is normal that the game doesn't allow me, the play, to shoot a Fire Bolt or Magic Missile past 18 meters (60 feet) when the range in D&D 5e is 120 feet, but the enemy can throw potions at their allies or vials of acid/fire at the enemy twice that range?
Oh, and I forgot to mention in my original post that yesterday, I put a Fog Cloud in-between my party and some distant goblins a little below me to prevent them from shooting at me... and guess what? They could shoot me through it just as if it wasn't there! They must have had Truesight 120 feet, because normally, you CANNOT SEE through heavily obscured areas, and therefore you CANNOT TARGET creatures with ranged attacks.
EDIT : Right after I posted this reply, I went back to the game to redo the whole goblin camp. As I attacked the sleeping bugbear at the upper level, everybody IMMEDIATELY woke up, ready for combat (no turn of waking up, figuring what's going on? How did they even wake up anyway?), and the bugbear goes first, shoves my fighter TEN METERS AWAY from him (still no Strength contest) down to the base floor and then goes to attack another party member. That's 30 feet. There isn't a single creature or mechanism in D&D 5e that allows shoving back 30 feet, let alone without any saving throw.
2nd EDIT : I reloaded the game just before attacking the bugbear in its sleep, this time putting ALL my party as close to the wall as I could. He still shoved my character 10 meters away down the ledge.
You have to approach this as its own game with its own crazy homebrew (think of it as a very drunk DM who opened the 5E player's handbook for the first time the night before) rather than a strictly 5E adventure by a digital version of your regular DM. Sure, you largely know what's going on, but take nothing for granted. That said, there really is no introduction to just how much you can move enemies and objects with shoves (and how much they can move you), and there certainly should be come full release. But once you know about it, you can start planning for it.
If a gobbo can throw something at you from 30 meters then that sounds like a bug. I have not seen that happen. Mind you, distance for ranged attacks and throws is a bit weird, and you can at times attack beyond normal range, but 30 meters almost certainly should not be possible.
Fog Cloud, yes, that spell is buggy at the moment. Rather than actually being a visual blockade, what it does is impair blindness on anything inside it and I *think* that it also makes anything inside unable to be attacked from the outside. This does make the spell rather less useful, however it is not considered an attack and characters inside the fog will move away. Visual range inside the fog is zero. This means a particularly exploitative kind of player could use fogs to make it trivial to pickpocket potions and special arrows away from all the gobbos before starting the fight.
Regarding shoves, there actually does appear to be a resistance check, presumably with the DC being the shover's athletics versus the shovee's athletics or acrobatics, whichever is higher. Bugbears are pretty strong so they're not bad at shoving. That said, it really does sound to me as if you're not positioning a whole lot before that fight and you're giving the grunt a good angle. Also possibly without really doing much to avoid being in LoS from below. I have not really checked out the gobbo hole mechanics much, but do notice the raised plateau right next to those bugbears. That's probably where you want your party members, if hugging the weakened wall isn't doing it. I would very strongly recommend ungrouping your party (there is a button for this now, but it is unassigned by default) and finding good positions for them individually.
A 10 meter shove does sound rather ridiculous, though. Would your fighter be a dex-based hafling or gnome or such? And I'm assuming without proficiency in acrobatics? Otherwise it sounds like a bug more than anything. I have not seen normal sized characters get pushed that far by other normal sized characters, but I am fairly sure that shove distance is affected by shover strength and size versus target's weight and maybe size. Which makes sense, you have to admit, even though 10 meter shoves from unexceptional enemies is of curse quite ridiculous.
Edit: I just noticed your other topic on that shove, and it seems like you fell down a pit? That does change things. Obviously that's not how a drop works in real life, but the game seems to maintain your horizontal movement speed during descent, so the further you fall down, the further you move horizontally. And moving 10 meters that way is very possible, even though it is obviously nonsense.
