Are you using public proxies or proxies with different geo loacls?
Its not that scrapebox is not being reilable, scrapebox always gives you back what it gets. But if it gets different data each time, then it will give you differen things.
My recent experience with this is that google used to give back the same data for indexed domains across all googles. But lately it has started giving unique data for some googles.
So if you are using ips with different geo locals your getting results back from different googles. Any given url may be indexed in google France, google Italy and not google UK for example. So this isn't a unreliability in any way, its that google returns different results.
Now I would "guess" and I have not verified this, its just a guess, that this is true for weaker urls/domains. I mean if your site/url is "strong" enough or authortitative enough its no question all googles will carry it, but when its edgy or weaker, then google may say its valid for markets A, B and C but not X, Y and Z.
Turn off proxies and try a handful of urls several times, or use just 1 proxy (assuming that you don't wind up with any errors from the proxy) and you will likley see consistent results.
Meaning the inconsistently, if you can call it that, is due to variance in IPs.
More importantly its not really an inconsistency at all. I mean if that is the truth of what google is doing, maybe its just an indicator your urls/domains are either deemed invalid for given markets or to weak/not authoritative enough and you need to go to work.
The thing is, people assume its either indexed or not, but in reality, if there are 100 googles (I know there are more, Im going for round numbers here) you may indexed or not indexed any any of them and thats not an inconsistentcy, thats a reality of how google works now days, a reality that we need to learn to live with.
So the important questions are, is it indexed for the markets I want to work with?
or
How do I make the links "Strong" enough they get indexed in all googles.
Its not just indexed by the way, I See this now across the board. Meaning search results vary for users, even on the same engine, but different ips. I have seen it for a couple years in rank tracking.
People complain they see a different rank then the rank tracker. Thats irrelevant, what does the end user see? Because if 80% of your userbase sees what the rank tracker sees (because people usually blame the rank tracker and say its "Wrong"and what they see is "right") then the rank tracker is indeed "rigth" and what you see is wrong.
But in reality there is no wrong or right, there is only proof that as time goes on google delivers a different experience to different users and they why and how of that just keeps increasing in its diversity and complexity.
my two cents.
) .