not returning valid UTF-8 for some of the tweets
This seems like a Nitter bug. It's not returning valid UTF-8:

`% curl 'https://nitter.net/UPTRBE/rss?max_position=HBaAgLell%2BmliyUAAA%3D%3D' | isutf8 -
(standard input): line 198, char 151, byte 16846: After a first byte between C2 and DF, expecting a 2nd byte between 80 and BF`

https://validator.w3.org/feed/check.cgi?url=https%3A%2F%2Fnitter.net%2FUPTRBE%2Frss%3Fmax_position%3DHBaAgLell%252BmliyUAAA%253D%253D also reports that the original Nitter feed is invalid:

`Sorry
This feed does not validate.
'utf-8' codec can't decode byte 0xc3 in position 16846: invalid continuation byte (maybe a high-bit character?)`

Also compare https://nitter.net/UPTRBE/status/1330932329288765443 to the original https://twitter.com/UPTRBE/status/1330932329288765443 -- there's mojibake at the end of the link text.

Affected URL: https://nitter.net/UPTRBE/rss?max_position=HBaAgLell%2BmliyUAAA%3D%3D
there are many other user tweets not returning valid UTF-8. Can you kindly look into it?