Is there an existing issue for this?

• I have searched the existing issues

Is the issue reproducible in Notepad++ without plugin?

• I have tried Notepad++ without plugin

Is the issue reproducible in portable version of Notepad++?

• I have tried portable version of Notepad++

Does the issue affect SciTE?

• I have tried SciTE

Description of the Issue

I am reporting a rendering bug encountered when editing files with a extension .bat. When a single line of text reaches a certain length threshold, the display begins to render incorrectly, as shown in the screenshot below.

The Chinese character '机' incorrectly renders as its UTF-8 hex representation: \xE6 \x9C \xBA.

Key Observations:
Scope: This issue appears to be specific to the file extension..bat

Comparison: When the same content is saved with other file extensions (e.g. .txt), the text renders normally.

Steps To Reproduce

1. input the following code:
   python .\fetch.py "159915.SZ,588000.SH,159601.SZ,510050.SH,510330.SH,512500.SH,159845.SZ,159532.SZ,159628.SZ,159949.SZ,159967.SZ,159901.SZ,588030.SH,515180.SH,515450.SH,512040.SH,159758.SZ" "创业板ETF易方达,科创50ETF,A50ETF,上证50ETF,沪深300ETF华夏,中证500ETF华夏,中证1000ETF,中证2000ETF易方达,国证2000ETF万家,创业板50ETF,创业板成长ETF,深证100ETF易方达,科创100ETF博时,红利ETF易方达,红利低波50ETF,价值100ETF,红利质量ETF" "price_data.csv"
python .\fetch.py "159611.SZ,159667.SZ,159735.SZ,159745.SZ,159766.SZ,159843.SZ,159851.SZ,159852.SZ,159855.SZ,159883.SZ,159995.SZ,159996.SZ,159997.SZ,159998.SZ,162411.SZ,159647.SZ,159786.SZ,512170.SH,512400.SH,512690.SH,512800.SH,512880.SH,512980.SH,513090.SH,513180.SH,513400.SH,513860.SH,515030.SH,515050.SH,515210.SH,515220.SH,515250.SH,516110.SH,516150.SH,516670.SH,516970.SH,560280.SH,562800.SH,501312.SH,512200.SH,512600.SH,512660.SH,513060.SH,513100.SH,515790.SH,515950.SH,516020.SH,516560.SH,516770.SH,516910.SH,562500.SH,159515.SZ" "电力,工业母机,港股消费,建材,旅游,食品饮料,金融科技,软件,影视,医疗器械,芯片,家电,电子,计算机,华宝油气,中药,vr,医疗,有色金属,酒,银行,券商,传媒,香港证券,恒生科技,道琼斯,港股通科技,新能源车,通信,钢铁,煤炭,智能汽车,汽车,稀土,畜牧养殖,基建工程,工程机械,稀有金属,海外科技,房地产,消费,军工,恒生医疗,纳斯达克,光伏,医药龙头,化工,养老,游戏动漫,物流,机器人,恒生生物科技" "price_data_ind.csv"
python .\cal.py price_data.csv
python .\cal.py price_data_ind.csv
pause
2. save as test.bat

Current Behavior

Display text abnormally

Expected Behavior

Display text normally

Debug Information

Anything else?

No response