在line chrome extension，常常看到 \ 顯示成 ¥，其實這是因為字型的問題，部分日本字型會有此行為，其中一個是Gothic字型
原因可參考: https://tex.stackexchange.com/questions/406247/yen-%C2%A5-symbol-for-backslash-in-texworks
Some Japanese fonts, e.g., MS, Yu, IPA, and Meiryo, render U+005C (REVERSE SOLIDUS) as a yen symbol while yen symbol is assigned to U+00A5 and 0xA5 in Latin-1 encoding. This stems from the fact that the code point 0x5C in Shift_JIS means yen symbol. Developers of the fonts above decided to employ a yen symbol as a glyph for U+005C so that inexperienced users do not get confused with the change in the appearance of the character. Therefore, what the OP considered as a yen symbol is actually a backslash that mimics a yen symbol (ridiculous phrase but I hope you understand the meaning).
https://tex.stackexchange.com/questions/406247/yen-%C2%A5-symbol-for-backslash-in-texworks
在line chrome app中很明顯是對到了日本字體造成的，仔細去看他的css，會發現
在Gothic字型前是微軟正黑體 但是應該要拼成 Microsoft JhengHei而非MS JhengHei，所以瀏覽器就對到第二個順位的字型，MS PGothic，這也是為什麼會看到 \顯示成¥ 的原因