R version 4.2.0 and Swedish letters (ä ö å) not working in newest R release. Anyone found a solution?

Question

I have updated to the latest R release (R version 4.2.0), but I am now facing the problem that all the Swedish special letters cannot be read anymore. I am working with a database that has many Swedish letters in its factor lables and even if I am reading them in as strings R doesn't recognise them, with the consequence that all summary tables that are based on these factors as groups are not calculated correctly anymore. The code has been working fine under the previous release (but I had issues with knitting Rmarkdown files, therefore the need for updating). I have set the encoding to iso-5889-4 (which is nothern languages) after UTF-8 has not worked. Is there anything else I could try? Or has anyone come to a solution on how to fix this, other than to rename all lables before reading in the .csv files? (I would really like to avoid this fix, since I am often working with similar data)

I have used read.csv() and it produces cryptic outputs replacing the special letters with for example <d6> instead of ö and <c4> instead of ä. I hope that someone has an idea for a fix. Thanks.

edit: I use windows.

Sys.getlocale("LC_CTYPE") [1] "Swedish_Sweden.utf8"