Hi, I noticed that the encounter builder recently got an update, and with this, it removed a prominent feature. You can't remove PC's when managing encounters and you can no longer just type # of # level PCs. The other issue I noticed is that the encounter builder has lost a substantial chunk of computing power. Before the update, I could simulate ridiculous encounters, specifically 300,000,000 Monodrones. Now the encounter builder caps out at around 1,000 before the page crashes.

I have no plans for making encounters that large I just like to see how much XP you'd get if you survived.

Why was there a removal of the mechanic that allowed you to start an encounter that you had just built. I now have to back out and go back in the initiate the encounter. Plus, almost every time I try to click on my encounters it takes me to dice and my dice takes me to my campaigns. 

I run my encounters and campaign off my iPhone so I was using safari. I just attempted to use the builder in the same manner on chrome and in incognito mode and both presented the same problems. When I go into encounter builder pick my campaign and add monsters it opens the encounter summary screen. I would then hit save encounter. Before now when I hit save encounter it would open up the screen you posted in your reply and the run encounter would be there. However, now when I press save encounter it presents a save icon and the screen does not change. I then have to leave encounter builder since there is no way to navigate to specific screens in encounter builder unless you follow the forward linear progression. Then I have re-enter my encounters which is complicated since my encounters button takes me to my dice almost every time. When I go back into my encounters I can click on the saved encounter and it opens the proper screen and allows me to run the encounter. 
I checked my phone and I don’t have any add blockers activated and I don’t use VPNs or any such thing. I’m not sure if what I’m describing is intentional since only have my prior experiences with encounter builder to go off of

I am also experiencing difficulties in changing the number of characters in the party as well as the levels.  I can add but I am unable to subtract the number.  Also since the update, characters no longer are separated by letter (character a, character b etc). Lastly, I have 2 encounters that are frozen under “my encounters and are unable to delete.   I throughly enjoy this feature, but the new update has created some difficulties for me. Thank you for your input. 

Try turning your device into landscape mode.

Just a side note - the issue with the menu links on mobile devices with Encounters going to Dice, and Dice going to Characters has been resolved. So it should now be easier to navigate to the Encounter Builder whilst on mobile devices.