Sorry, I know there's gotta be a lot of posts with similar topics, I just want to make sure my situation isn't unique. 

I'm on the constant search for old wallets and have successfully found some.  They're all in Bitcoin core.  I've downloaded the complete wallet (360+GB) and copied my wallet.dat files into the appropriate folders.  The wallet shows there's (barely) funds... but when I go to do a transfer it gives the error "0/unconfirmed, not in memory pool."  I've read this is either due to do a unsynced wallet (which I'm confident is not the case after 2+ days of downloads) or a insufficient transaction fee.  At first, I sent with the bitcoin core recommended transaction fee and after an hour,I doubled it.  It's now been roughly 2+ hours and still nothing.  Am I missing something here? Is it really supposed to take this long?

Side note, I believe I'm sending from a legacy address to a segwit.

Thanks for your help!

I was an early adapter of BTC mining.  Like many posts on here... I've gained and lost my fair share of BTC's for the last decade and I'm now on the hunt for what I once had.  While I don't have an encrypted HDD that I can't remember my password to, I do have an old blackberry that I can't remember the simple screen lock code lol.. But that's not the point of this post/question!

I've learned my lessons (the hard way... FlowerTech, 50BTC...) and I'm now acting smart on how and where my crypto is stored.  But like many others, the hunt for old wallets is ongoing... it's a fun treasure hunt!

I've read some posts that state that there is software out there that can scan old drives for files that resemble wallets.  I know there's always risk, but is this true? If so, recommendations, insight, feedback?

Thanks!