Can you provide a link to a document where this occurs? Also, can you take a screenshot showing the problem, upload it somewhere (Google Drive, Dropbox, etc.), and provide a link here?
I faced the same problems. When I open a pdf file with zotero reader, the font of the pdf file produces a change and produces the problem of not being able to highlight the text properly.
Upgrade Storage
https://pic7.58cdn.com.cn/nowater/webim/big/n_v2af7cd3eac692480abffbe4431c4437e4.png
The pdf link： https://flowus.cn/7c3217a4-c4c6-400f-ade6-a60076aad00e
@wugeng668: That first link doesn't work for me and the second requires an account to download the file.
We need public links for everything, or you can email files to support@zotero.org with a link to this thread.
Link：https://pan.baidu.com/s/1LfIWuxSzE_89red4ExMAHw?pwd=z63q