Some previously accessible protein IDs are no longer searchable in the AlphaFold database

Hi, I am writing to report an issue regarding the search functionality of the AlphaFold database at https://alphafold.ebi.ac.uk/. I have noticed that certain protein IDs (such as Q01628) that were previously searchable and from which I successfully downloaded predicted structures can no longer be found via the search box on the website.

My main questions are:

1. What are the primary reasons that could cause specific protein entries to become unavailable for search in the database?

2. Are the previously downloaded PDB/CIF prediction files for these IDs still valid and suitable for continued analysis, even if the entry is no longer listed online?

Thanks!