Erroneous translation results when attempting to translate a text in a different language

[acornestean]

[Affected versions]:
Firefox Nightly (94.0a1/20210920212918)

[Affected Platforms]:
Windows 10 x64

[Prerequisites]:
Access https://mozilla.github.io/translate/.

[Steps to reproduce]:

1. Translate any text from EN to RU.
   For example, use: “Giovanni Antonio Grassi (10 September 1775 – 12 December 1849) was an Italian Jesuit who led many academic and religious institutions in the United States and Europe. Born in Lombardy, he studied at the Jesuit College in Polotsk, where he began his academic career. He was soon ordered to China as a missionary, but after traveling across Europe for two years attempting to secure passage, his orders were rescinded and he instead began teaching at Stonyhurst College in England.”
2. Once the translation has finished, copy the translation results and paste it into the “From” field
3. Cycle through the “From” languages while setting and keeping EN as a language to translate to. Wait for the translations to finish
4. Observe the erroneous results.

[Expected]:
Maybe the engine should detect the input language and change the “From” language to the one detected so as not to get such results.

[Actual]:
When the engine attempts to translate a text which is in a language different from the one selected, the translation result is erroneous.