Martha Stewart's criticism of Ryan Reynolds' "very serious" off-camera persona should be taken with a grain of salt ... given the fact the actor's been quite vocal about his past anxiety hurdles.
A source close to Ryan tells TMZ ... the actor has made no secret about his anxious and racing mind ... which means sometimes he shuts down around people.
As our source puts it ... Blake Lively's husband likes being quiet over being "on" ALL the time.
While Martha seemed to have a strong take on the "Deadpool & Wolverine" star's personality ... our source says MS doesn't actually know Ryan all that well. We're told he's met Martha only once or twice, and he's not sure what she was expecting.
Again ... we hear the 2 only chatted very briefly at a party or 2... hardly enough time to gage someone's (real life) personality.
The businesswoman made headlines this week after she claimed on the "Rent Free" game show that Ryan was "not so funny in real life," saying she'd rather hang with Brad Pitt and George Clooney IRL.
Though, Martha made it clear she still has a soft spot for Ryan ... defending he's a "good" and "funny" actor, but just not a barrel of laughs to hang with ... in her opinion.
Ryan initially issued a cheeky response on X as the comments went viral, writing ... "I’d disagree with her. But I tried that once. The woman is unexpectedly spry. She really closed the gap after a mile or so."
Hugh Jackman, who has a playful faux feud with his best pal, Ryan, also gave a tongue-in-cheek comment, adding ... "Finally someone says it."
Still, Ryan has been open about struggling with anxiety since childhood ... so, Martha may want to lay off the criticism without knowing the full story. Just sayin'!!!