Two examples I can think of:

"It's a tie", as in a draw, translated to mean "it's a necktie"

"Roger that" translated to mean "that must be a man named Roger"

I can't think of an example right now but I absolutely cannot watch French films with English subtitles and vice versa because I spend too much time raging at inaccuracies. Or I get caught thinking about how I would translate something myself and I quite literally lose the plot.

I get that translation cannot always be 100% accurate to account for cultural differences for example, but sometimes it's just plain wrong.

Tons, I know tons. Some of them even get into the cultural zeitgeist as jokes. For example in Final Fantasy VII they translated "Your party is waiting for you on the second floor" as "Su fiesta le espera en el pisos 2" (if you don't understand Spanish, they translated party/group as party/celebration)

Yeah, Japanese subtitles can have issues. Various broadcasters have been caught saying something else, though usually only when they overdub so one can barely hear the actual person.

Since Dutch as a language is generally not big enough to make dubs profitable (the exceptions is media specifically meant for young kids) almost everything her is subtitled. Subtle here are mostly quite good. Sometimes I notice it doesn't match exactly what is being said but then it does have approximately the same meaning. I never noticed examples like yours from english to Dutch, but I don't watch a lot of TV anymore.

Like half of the subtitles between English, French, and Spanish get mistranslated

Loads. I just binged "One Piece" (the real life version), with English Audio and German subtitles. The amout of text that matched the audio was neglectable.

Let me introduce you to Backstroke of the West

I can with Mandarin and English and there are many words that both languages don't have. Also in Mandarin there are different levels of respect/ tones when speaking to an elder or a boss that gets completely lost in translations.

Not exactly, but there are cases when a joke doesn't make sense in my language, then in literally translate to English and I get the original joke. I remember this with Toy Story 5, but I don't remember the joke.

I'm from Finland and usually the subtitles for English content are good.

One challenging example that comes to mind is Baby Shower. Since this concept is mainly from the US, there isn't an equivalent term in many languages. People here usually just use its English term, but I've seen subtitlers sometimes translate it as vauvasuihku, which literally means "baby shower", but no one is going to understand that term.

In one series, there was the phrase “What is this, my shower?”, when a pregnant woman was asked if she had already chosen a name for the baby. The subtitler had translated this literally as Mikä on tämä suihkuni? (≈What is this shower of mine?), completely losing the context.

There's multiple ones, more prevalent with the use of ai. Like translating the 'render' that is an computer generated image in the meaning of plaster work.

But before that I remember a Dragonball Z episode where Gohan says to Krillin 'lets amscray' being pig Latin for 'scram', was translated like 'to amscray' was a verb in the DBZ universe. That's not a big mistake, but still it stuck with me long enough to be the first example to this thread's question.

Most of time cross culture is the issue which is your issue here, while rarely you will see subtitles mishaps which is because many shows nowadays offer offical subs or atleast have fan subs compare to old days when they were symbols like box or time adjustments issues not saying today perfect though as it still have the issue you have above unless you know culture of that medium you are watching

Watched Avatar: The Last Airbender with Hebrew subtitles, there were loads of mistranslations. Sometimes stating the exact opposite of what the English original said, other times the transistor just completely doesn't understand what they're translating and results in random nonsense statements. Sorry I don't have any specific examples, but really it's too common.

Lest you think it's because it's a kids show: more recently I've been watching Shakespeare & Hathaway: Private Investigators with my mom (a British cosy mystery comedy-drama television series, thanks Wikipedia), and mistranslations in the subtitles are just as common.

It really makes me worry about how common similar mistakes could be in e.g. Japanese content (anime, video games) subbed to English. I don't know any Japanese, so my ONLY source of information is the English sub, and if it's as flaky as the Hebrew subs for English sources, I really could be missing out :(