I've never had a complaint about the bokeh on mine, I see your images and agree that's not very appealing. However, I think the prior post is right, you my be too close to your focus point. I found it odd that the F5 shot had a better looking background than the F4 shot. Likely due to the distance from you to the focus point.
|Moon 99% D55 C14 St-Zénon 20170806 DP by MarioSS|
from Best Picture of the Week
|Reeds on lake by kkardster|
from Abstracts in Nature
|Florence & the Machine by Dutch Newchurch|
from Second chances..