Locked Out !

I'm an established Garmin user just bought and used the Venu X1 for my first pool swim ....

Things did not go so well.

I started the swim and the screen was locked during the activity automatically.  A minor inconvenience not being able to change screens from that default shown   (not including distance!) to say another one during activity.

HOWEVER

After Swim the screen is still locked and there is no **&@^@& way to unlock it.

Short pressing top right and bottom right buttons works to start and stop and lap activity which I dont want

Long press top right or bottom right buttons does what I programmed them to do in non activity modes ie for me  top right = control  (the equivalent of the circular panel on say my 970 press and hold top left)

Long press bottom right switches on and off the LED light.

30 minutes later I and the whole [tech savvy] family has had a go at unlocking.  We looked at the online manual

https://www8.garmin.com/manuals/webhelp/GUID-C144B465-A0C8-4FE9-AFE6-41A3FE3F1D9A/EN-US/Venu_X1_OM_EN-US.pdf

We tried tapping and holding, and swiping down for touch lock.  NO WORKY

We held and pressed the two buttons together , very long time.  We managed to summon 'crash assistance' and eventually powered off the watch

Now I pressed top right and the blue triangle is there for over 5 minutes now,  so the watch does not even seem to be rebooting correctly.

Main question is   :  How should I have unlocked the watch

Sub Question is:  When the Blue triangle of boot seems to be the blue triangle of death, is there a recommended recovery action?