Was My Late Husband In The Chain Of Title?

Location: MO. Sorry, this is long. At least I use paragraph breaks.

In 2010 I created "The CleanCalligrapher Revocable Living Trust dated (Month) (Day), 2010" which I'll call the Trust. DH was 15 years older at the time and had health issues so we knew it was likely he'd go first. It named my brother as Trustee and allowed for DH to remain in the marital home as long as he needed/wanted to if I died first. We bought a house in 2015. I wanted him on the mortgage so it would help his credit rating since practically everything else was my name only.

House was conveyed to "Trust and Mr. CleanCalligrapher, a Married Man".

He died in 2016. I'm selling the house with a closing date of July 1. Yeah, less than a week. The title insurer for the buyer has been an absolute train wreck. Only one example: They hounded me for our title policy, which I finally found, because there was an "unpaid lien". Said lien turned out to be the mortgage the sellers took out when they bought the place in 1995. Extremely unlikely it was not paid when we bought the house. I did a search in the public records and found the "Satisfaction of Mortgage" document and sent it to them. There's more. I'll spare you.

The issue that has me typing this at 3:30 AM: they think the granting clause should have been to "Trust and Mr. CleanCalligrapher, with Right of Survivorship" and that because it does not, he's still in the chain of title.

First: Does a granting clause with right of survivorship even make sense when one of the parties is a trust? Trusts don't die. They get revoked.

Second: I've had the trust re-written and subsequently updated since DH died and neither lawyer recommended doing anything to change the title to the house. DH had very little in his name, the estate was not probated for that reason and he had no will.

Now they're freaking out because DH's on-line obituary lists two children, one of whom is a stepdaughter and the other his bio son. He and I had none together. Based on what I believe is their faulty conclusion that DH is still in the chain of title, they think Bio Son may file a claim for a share of it. (MO intestacy law gives a % of the estate to surviving children- otherwise surviving spouse gets 100%.)

I've lost touch with stepson (SS) but a quick search of the snoop sites gives hints of addresses and phone numbers for $10 or so. But..

Third question: Even if you accept their conclusion that SS has rights to the property, isn't the statute of limitations for making a claims past? He was aware of DH's death in 2016. I even sent him $$ DH wanted him to have shortly afterwards. If he were living next door I'd wonder about having him sign a quit-claim deed but time is getting VERY short. I think he'd sign it (DH and I had discussed the outcome of the estate with him in person before DH died so he knows it's what his father wanted) but hate to go down that path.

Nightmare scenario: New owners move in and rent till we clear this up. I'm moving to a retirement community in another state and all is signed, sealed and delivered up there.

I appreciate any wisdom you can provide.

Update:
Well, so far I'm screwed. Got on two "snoop sites" and tried to reach stepson, his half-sister, his mother, and his ex-wife. All either wrong numbers or non-working except for one message I left for his ex-wife. Also sent messages to all the e-mails I found for all of them and only a few bounced but no answers. Same with messages to half-sister and ex-wife on LinkedIn.