Small business cybersecurity concern google search question

Hello All,

Our products are very innovative in a competitive market, and we have been very careful with our online presence. However, without offering all of our products online, we won't be able to succeed.

We have also been battling unexplained security issues (store disconnecting from payment gateway, plugins removed, clients complaining of order processing issues even though they do not appear on our side, etc.).

We have tested for malware, intrusion, scanned everything by various means, changed web design from scratch, passwords, login data, etc. That seem to have eliminated the majority of the issues (although this might be temporary again), but we noticed something really strange and hope that someone here might be able to point us into the right direction.

When 'running' a Google search for the first time, we get a result that fits our needs. Going back the next day, running the same search does not show any of the previous results anymore. Sounds weird, and for a long time we thought that we just don't remember. However, tested it on another computer simultaneously with the second computer showing the same result as the first one a day before. In the second search, it appears that when ever we run the 'same' search again it does not go to google page 1 anymore but rather jumps to page 1000 which will not answer any of the questions we originally had. This also applies to name searches. For example, looking for a person 'John Doe, Rockford, IL email address'. Will result in several John Doe listings with email, LinkedIn, twitter, fb, and what ever else and or in the city we asked for. Running that exact same search later in the day or days later will not show any of the previous results, but list a history professor named John Doe who wrote a poem about someone living in Illinois in the 1800s.

We now had a developer mentioning potential sabotage and suggested reaching out to cybersecurity experts. How would we be able to find someone to solve or help with this? Has anyone ever heard of this before?

Thanks in advance