Hey everyone, I need some expert help with a rather complicated case.

I used to run a gaming community for a specific niche, which was quite successful between 2009 and 2014, becoming one of the largest communities (with news and forum) in the DACH region. However, in 2014, I decided to shut it down due to personal reasons (kids, family, etc.).

In February 2024, I decided to revive the project using a database backup. Since the original domain (ending in ".org") was held by domain squatters, I relaunched the site under a new domain with ".eu" instead. A few months later, I managed to buy back the original ".org" domain and set up 301 redirects from all the old backlinks to the new domain. (The property is also configured in google webmaster tools and marked as "transfer to the new one").

Initially, Google indexed the new site very actively, despite some technical challenges with redirects and issues with the old platform. At one point, over 1,000 pages were indexed but the visibility, impressions and ctr was really bad.

However, due to performance problems, I decided to rebuild the entire application from scratch (with new structure and not the typical news/forum structure - its more like reddit now). The new version launched in November but had significant issues, leading to numerous 500 errors. It took me more than two weeks to fix everything, and in December, I also resolved the remaining redirect issues between the old and new domains.

Now, the real problem: Google has been continuously removing pages from its index. From over 1,000 indexed pages, only 4 pages remain today.

What I've Checked So Far:

• Page speed (optimized)
• robots.txt (no disallow issues)
• Meta tags for robots (set to index, follow)
• Audits with Ahrefs and Screaming Frog (no obvious issues)
• google webmaster tools

Additionally, I checked the situation in Bing Webmaster Tools, and it’s completely different. Pages are getting indexed, and rankings are steadily improving and the bot is very active. Currently, I'm happy if I see the Google bot crawl my site even 20 times a day. And most of the crawls is updating the cache with the js/css files from the page...

Has anyone experienced something similar, or does anyone have insights into what might be happening?

Would really appreciate any guidance!