Is there something Im missing or is everyone else playing wrong when runner successfully access HQ.

Just saw a couple of Netrunner videos on youtube and/or Team Convenant Twitch channel (like the one yesterday) and everytime the runner made a successful run on HQ (where he was allowed to access more than one card) the corp player shuffled the hand together with the first accessed card.

According to rules the accessed cards only go back to hand (if not either trashed or stolen if applicable) after all accessed cards are resolved.

So? Whats going on?

Do you have a link to the video in question?

you're right that it's not correct. "Accessing Multiple Cards from HQ: When the Runner accesses multiple cards from HQ, the cards are accessed one at a time, and do not return to HQ until the Runner is finished accessing."

The one exception that comes to mind is if Leela is multi-accessing and pulls an agenda on the first card, the card she bounces back to hand gets shuffled in before she continues accessing.

It may also be a bookkeeping shortcut, where the runner can get in for little or no cost, and just keeps saying "run HQ" two or three times in a row and then pays for it all at the end. If there were a Komainu guarding HQ with a Femme token on it, for example, you'd bypass for 0. Or else the corp is poor and can't afford to rez ice, so you run-run-run while there's the window of opportunity. You could simply keep pulling one card at a time for as long as you wanted to keep running.

But, you did say that there was multi access in play. Sometimes people screw up or have misconceptions in their head about how things work.