The citation key generator never preserves citation keys while importing from sites such as INSPIRE HEP. The citation keys are overwritten even if "Overwrite existing keys" is disabled in preferences and always without warning.

JabRef version

JabRef 5.3--2021-02-03--242a494
Mac OS X 10.15.7 x86_64 
Java 15.0.2 
JavaFX 15.0.1+1

• Mandatory: I have tested the latest development version from http://builds.jabref.org/master/ and the problem persists

Relevant links

1. JabRef renaming keys?! (I don't think these options exist anymore)
2. InspireHEP and SAO/NASA ADS Bibtex Key Catch (feature request)
3. Can I use Inspire citation keys when importing via jabref?
4. There is a mention of unwanted key formatting in Issue with INSPIRE web search #7274

Temporary workaround

It is possible to keep citation keys by using the citation key pattern [CITATIONKEY] during the import.
: must also be removed from the "Remove the following characters" field in preferences.
It should be possible to use the regexp in #7111 (comment) to create a workaround where a different pattern is used when there is no citation key in the imported entry. (If someone manages with this approach, feel free to add a comment and perhaps others will also find it useful)

Steps to reproduce the behavior:

1. Unmark "Overwrite existing keys"
2. Make a web-search on INSPIRE and import any entry
3. Note that the citation key is overwritten