Vic, it’s possible you might be able to get eyes on it by taking down the basement wall. I had a creak in the hallway floor and asked Redwood to take a look at the rally last year, and he crawled under there and shot a bunch of screws in the bracing. Just a thought. 

Posted by: @vmuschler

38REL, 2015 

Seems to have a soft spot on the floor.  Thinking I can inspect it by removing the top step kick board?   Thoughts?  Other members experience similar situation

No visible signs of water current or past.

Thanks

My FB had that as well. I was able to access from the basement to add bracing.

Also helped a fellow RWer add support to the steps by removing the top step.

Neither was from water damage just half a## construction.