Every time I try to animate a shapekey and place it on the timeline that shapekey stops working and the mesh doesnt update anymore from that point unless I undo, but then it happens again. Don’t know is just me or anyone else is having this problem. The keys work before putting them on a keyframe.
edit: this seems to happen after deleting a keyframe from the timeline
Blender 2.8 is still a ways from beta and as such is not ready for full production work. This is especially due to the many changes that could break any .blend file made with it a week from now.
In addition, the bug tracker for that version remains closed to everyone but the developers for now.
Yes i know 2.8 isnt even in alpha (or its entering soon) and the daily builds have bugs/glitches but just wanted to make sure it wasnt only me that was having this issue. I remember when modifiers werent even working months ago so I hope this also gets addressed in the near future.
No problem, here after a quick test on default cube.
It is totally normal behaviour to have one keyframe locking shape of a mesh.
You need 2 keyframes to obtain an animation.
no, what I’m saying is that animating shapes between values does not work and it becomes bugged usually after deleting one of them thats keyframed on the timeline. I do animations in blender so I know what I’m talking about lol.
Edit: I tested with the default 2.8 cube and confirmed that keyshapes are indeed broken. Heres what happens:
Normal software developing stages:
In development = If compiles is good. No guarentees to you or your machine. Neutrinos can explode and there will be monsters, using it will rise dramatically the possibilities that you will lose your job, your GF, your hair, and will be plain and absolutely NORMAL. YMMV. 
Alpha Software = All features complete, but you should consider everything broken by default. Explosions can happen. ( ) Until developers open the bug tracker, assume they know about their bugs.
Beta Software = All features complete and hopefully working, consider most features broken by default, but mostly minor, if developers have open bug trackers, bug reports should go there.
Release Candidate = All features complete and working with some surprises here and there, most features working OK by default.
Final Release = All features complete and working as intended, there can be bugs, but shouldn’t be many.
Since Blender 2.8 is in alpha stage, consider everything broken by default. 
It is just the piece of info I need to confirm the bug.
Obviously, there are problems with animation system. Moving a NLA strip is sufficient to obtain a crash.
As a workaround, it looks like we can create and delete keyframes at correct value in Graph Editor.
This is still not fixed.
It could stay as is during next 3 months.
2.8 is still at alpha state. Release of beta version was postponed to several weeks.
Official 2.80 should be released 3 or 4 months after beta.
And then, release cycle should be the same than for 2.7x series.
Nowadays, 2.8 branch have his amount of crash that have been decreased. But there are still lots of features to fix, some workflow gaps to fill old features to restore and new ones to complete.
For example, grid display and grid snapping were just fixed today.
Animators of Spring movie can’t ignore the issue. They are probably forced to use graph editor, too.
If it will not be fixed in upcoming days, it just means that they have other higher priorities.
But at the end, it should be fixed in 2.80.
I know this is an old post, but if anyone comes across this problem as of 19/02/2019, you can download the latest build and it should work fine.