The setting for my question can be found in another one right here on Workplace SE. To make it seem like a continuous story, I'll re-use the names for my coworkers.
It's now been a little over a month since Jake left us. We (as in me and Bob) tried to employ suggestions posted in the great answers there (apart from quitting, for now) with very little result. We feel the message was acknowledged, but not agreed with.
This week the manager in question went for holiday. Since day 1 we started receiving mails and calls to basically give him status updates on every single minute of our work time. This quite baffled us, as we were, up to this point, a pretty much self-managing team, which worked quite well, we handled cooperation, contact with our, let's say, clients, coordination of testing etc. (the only times we missed deadlines were because of things out of our control, but we always made sure to report, inform and do whatever we can to speed up the process). While, as explained in the linked question, due to the amount of work for me and Bob deadlines started slipping, we took it onto ourselves to keep the interested parties in the loop, why was their task delayed, by how much, how can we minimize the impacts and so on. Pretty much everyone understands that time is not magic, and if we don't have time now, they are fine with the new timeline, just keep them updated and provide honest estimates so they can plan around it.
An example would be that Bob (whose work time is 7 hr 40 min, as we get 20 min paid break), gave him a daily update with times he spent on his tasks which totaled to just short of 7,5 hours. He was then questioned extensively what was he doing for the remaining 10 minutes or so.
I found it (and Bob too) absolutely ridiculous, and we basically are 90% sure we will hand our resignations when he comes back, since, for reasons not know to us, the workplace is getting worse by the day.
We decided, however, to give it a last go to try and understand what is happening here, as we enjoy being in the team, the employees we work with and general atmosphere.
The question is: How can we, in a non blaming/overly confrontational matter discuss the issue of sudden behavior change with our manager? We received no feedback from anyone that something is wrong with our work, or that we need to improve on something, or anything. It's quite literally going 0-100 in a matter of 1 day. Morale has been down since everyone is wondering is it something we did, have we lost trust because of something etc.?