Botched domain migration

[sonar]

tldr: we consolidated several of our domains from longdomain.com to domain.com over a year ago and lost our highest value keywords, roughly 70% of our traffic.

All our links were natural google loved our site up until that point. Things started to go sideways then...

Oct 2016: 301 redirect everything from http(s)://(www).longdomain.com/* to https://www.domain.com/*, traffic starts to slump

Jan 2017: Traffic has slumped 30-40% from normal seasonal levels

Apr 2017: We experiment with Rankscience, implementation is botched creating a robots.txt disallow: / which is corrected in a week. traffic slumps even more during this period, but this issue seems to recover over the next month or two (hard to tell since now we have multiple factors and seasonal traffic).

Oct 2017: Start an engagement with a seo firm that has experience with migration issues. They find some pages which are not redirecting and claimed that google is confused by that and pages we were redirecting wouldnt pass all the pr value until every page on our old site (including non public ones that google seems to have scraped from emails) was redirected over.

Interm: Site audits from the seo form, many minor onsite improvements, link disvow, etc etc, no impact really.

Current day: Stumped, and the business is hurting from the lost rankings and cost of seo. Those high value rankings are just gone and I did everything by the book as best I know. Redirects, same content, just punished.

Up until the interacting with Rankscience and the seo firm, I handled all the serp related concerns myself. This has left me pretty disillusioned and at my wits end on where to look next.

[davebuts]

Hi Sonar,

Sorry to hear about your migration troubles!

I don't think you will find generic advice too helpful, but I'd be happy to take a quick look to see what's going on and possibly give you some specific recommendations.

Are you able to share the domains with me in this thread or through PM?

Cheers,

David

[sonar]

Hi David, I will shoot you a PM, I think thats best. Thanks for your offer.

[sonar]

One more detail of note

The old site still shows in google site: search, two full years after everything is 301'ed.

Change of address was not used - is that critical to ensure that PR passes?

If so - it doesnt allow redirecting into a subfolder - what do you recommend in this cases - temporarily change our 301 to point to newsite.com instead of newsite.com/subfolder in able to get past this blocker in the GSC change of address tool?

"The old site redirects to newsite.com/xxxx, which does not correspond to the new site you chose."