This is evident when I show what handwritten Japanese (Kanji only without any Kana) looks like, they still mistake it for Mandarin (due them being logographic), the same applies towards google searches too, as when I type a Japanese word in Kanji (despite having the UI and browser set in Japanese or English) I still get results in Mandarin since all the websites contain the TLD .cn or .tw when I am looking for Japanese websites ending with (.jp).
If a person is clueless about distinguishing the differences between languages (especially ones that look similar when written even though they’re different, kind of like when writing in French & English but they’re still different languages), then they fall into the trap of “Is that French?” or vice versa for example, when in fact it’s written in English. Does this word all look the “same” to you or not when telling the difference between 日本語 or 中文?.

You get the point, I still get comments equivalent to “is that Chinese?” when there’s kana present within the sentence (which Mandarin does not have, as they write entirely in Hanzi). Some words are written the same but pronunciation is very different as they’re unrelated languages. Does the same thing happen to let’s say Norwegian & Danish (or any other European language) since both pairs use similar alphabets and have an identical writing system?
From Japanese or Mandarin, there are characters that look the same but have different pronunciations altogether like:
| - | 日本語 | 中文 |
|---|---|---|
| 擲弾兵 | てきだんへい | Zhì dàn bīng |
| 艦隊 | かんたい | Jiànduì |
| 陸軍 | りくぐん | Lùjūn |
| 神社 | じんじゃ | Shénshè |
| 地獄 | じごく | Dìyù |


As an English speaker who’s dabbled in other Germanic and Latin languages, absolutely. I dislike Dutch specifically because it will either start to read like English or German then fall off the deep end real quick.
Portuguese (at least Brazilian) looks and sounds like a mashup between Spanish and French.
This is kind of to be expected when you look at the history of how these languages evolved. The reason Japanese and Mandarin would be so easily confused is that the writing system was imported from China and there are a lot of words that either still look like the parent words or very similar. The same for the Latin and Germanic languages as well as their related offshoots. The history of invasion, language mixing, adaptations, and standardization has produced languages that are in various levels of mutual understanding.
Even though there are words in both Japanese & Mandarin that are written similarly to one another or exactly the same but keep in mind pronunciation is different, such as 警察 (けいさつ) from Japanese but in Mandarin that’s pronounced as jǐngchá. Dutch and German are still different languages but are there also pronunciation differences for words that are spelled the same?
Not on the same level considering the difference in how the Eastern and Western languages are formed.
I’m generalizing a bit here into Western being Germanic or Latin based languages and Eastern being primarily Chinese.
Western languages typically use symbols that represent the component sounds of a language (phonemes) where Eastern languages use symbols for whole words or concepts (morphemes). So you would have a single symbol for house or tree instead of a series of symbols for the words.
This means that the word spelling would change in Western languages as the spoken language changes more rapidly and show a large difference between two closely related languages in their spelling for the same word.
Conversely, in Eastern languages, the spoken language is not as closely tied to the words used. (To translate into English as best I can: The character for house could be pronounced like house, home, building, cave, lean-to, castle, shed, etc depending on where it’s being said). So, you’d have, after a few generations, the same character pronounced two very different ways with two different meanings
Through through tough thought, I can’t think of any.