Maybe coincidence but problems for me seem to have started with change to daylight saving time here in the UK.
Most of my problems are PEBCAK.
I’m in similar situation with ID10T errors.
I was thinking of installing a fix for that where I work for our end users.
eject-abort.gif
I needed that for myself by the second day after going live with PDM.
You should try Windchill 
I doesn’t stay logged in here either. Yesterday, [and maybe day before] I had to log in once. Today, it’s already 2nd time in 2 hrs…
Ok, I’ve hired some help for this problem. Settings may change in the next couple of days. First change happened at about 10:15 am east coast time this morning. Let me know if it is better or worse.
I just tried my bookmarks to cadForum.net and it keeps me logged in now. That part is definitely better now. It does seem that there was one last extra login but I’m guessing that may have been caused by implementing the change(s).
It seems to be fixed for me. Thanks, and I’m sorry you had to hire help.
Same here. Thanks for getting it sorted.
And don’t be afraid to hit us up again for donations, if needed.
You don’t have to wait for him to ask. The link is right there at the top of the page. I just kicked in a few dollars.
Thanks to all who are kicking in. If this is the solution, it was pretty simple. None of it is difficult, there are just a lot of places to make the changes, and potential errors everywhere from individual browser settings to host server, and everything in between. Thanks also for the patience.
I’m a member of two other phpbb boards. One of them has the login/cookie thing figured out, and the other is way worse than this site. Unfortunately, I can’t get a response from the good board admin, but I shared our current solution with the bad board admin to at least get all the boards I attend on the right page. Phpbb is kind of a dated tool. Most of the activity on phpbb admin topic boards kind of fell off the map ~2016 or so.
There’s always the question “why didn’t you do this on Facebook?”. Well, I did facebook for the the first year or so, and then I dropped out. Same with twitter. You kind of had to join when they were new just to see what was going on. When it became obvious those platforms were mostly about collecting your information through addictive behavior, I bolted. Those platforms are so big they can force inclusion, and that just wasn’t me. I’m more of an independent sort, if that isn’t obvious.
Plus, does anyone remember the days when AOL chatrooms ruled the internet? Facebook too will pass.
That’s why we get to solve these petty issues like Spamhaus and login cookies ourselves. But it also gives us more control. By users For users is a pretty strong motto.
Facebook and related platforms…hrrggmm…cough…3dx…are like a stream of conscious medium. Ok for quick questions but not a serious place to hash out technical issues IMO. You can’t search and really find anything and posts get lost in the noise.
I agree with all of that, but in addition, I’m like matt. For a myriad of reasons, I will not go back to facebook.
Being easy isn’t the same as being obvious, and while you are a SME on a number of things, I don’t think PHPBB admin is at the top of your resume. 
All working fine here now, thnaks.
Only time i could remember site logged me out is sometimes if i open topic in new tab. Usually logging in fixed it