Lost several months of data after re-processing

Heyho,

a short introduction: We had to report on a large set of subpages. Here we ran into problems with the default Matomo configuration, which let’s you only see a maximum of pages in a report (the rest are then just accumulated into “Others”).

We then followed https://matomo.org/faq/how-to/faq_54/ to increase this limit and re-processed the data according to the FAQ. This has worked fine.

However:
We have lost data from several months. We have Users, but all ‘Actions’ (including Page Views etc) are lost in that area. See screenshot => https://gyazo.com/6db6431d69649f203653b9b156c285ff

Any explanation what went wrong here, or even how to perhaps restore data, would be greatly appreciated!