I don't know but ...
in the interest of full disclosure
I modify my configuration
(among other thing) by adding
[Services]
ContactUsURL=https://duckduckgo.com/lite
EulaURL=https://duckduckgo.com/lite
FirstTimeUXURL=https://duckduckgo.com/lite
ForgotPasswordURL=https://duckduckgo.com/lite
ImageHandlerURL=https://duckduckgo.com/lite
PartnerProxyHandlerURL=https://duckduckgo.com/lite
PrivacyURL=https://duckduckgo.com/lite
PurchaseURL=https://duckduckgo.com/lite
RequestURL=https://duckduckgo.com/lite
SecureURL=https://duckduckgo.com/lite
ServiceDomain=.duckduckgo.com
SignInURL=
SocialAuthorizationURL=https://duckduckgo.com/lite
SocialURL=https://duckduckgo.com/lite
WebsiteURL=https://duckduckgo.com/lite
WebstoreProxyURL=https://duckduckgo.com/lite
WebstoreURL=https://duckduckgo.com/lite
No adobe, drm, no kobo store = no drm kepub etc problems
... could that be why connections are problematic for others?
Most of the difficulties reported on the forum I don't experience
Just sayin' ... ???
2 bits