The “Long Press” action was removed from the “Feeds” tab with the release of version 1.2.4135 and up...the action to access the Feed/Podcast menu for your feed subscriptions is to press the context menu icon (Hamburger Icon Right of Feed Title)
(FYI) On the “Episode Screen” of feed/podcast subscriptions and the “Audio” and “Video” tabs, the long press action is now used for “Multi-Select (Bulk Operations)” feature to flag all or selected episodes as new/done and delete media files
From the “Feeds” tab>press to open a particular feed/podcast>on the “Episode” screen of the feed, long press on each episode>press the “Trash Can” icon to delete all selected episodes, press the “Person” icon to add all selected episodes to a new or created playlist, press the “Box” icon to mark or flag all selected episodes new (Blue), press the “Check Box” icon to mark or flag all selected episodes done (Grey), press “Push Pin” to delete “Pinned Episodes” from feeds with the “Pin Expired” feature is enabled.
The same “Multi-Select (Bulk Operations)” features are also available on the “Audio” and “Video” tabs
The previous “Long Press" actions for the episode menu are accessed with “Context” button (Three Vertical Dots or Hamburger right of the Episode Title) on the “Episode” screen of all feeds and “Audio” and “Video” tabs
This also applies for "Long Press" action for the feed menus and accessed by pressing the “Context” button (Three Vertical Dots or Hamburger right of the Feed Title) on the “Feed” Tab
From the feeds tab>scroll down to the feed/podcast>press the context menu icon (Hamburger Icon Right of Feed Title)>select "Delete Feed" > the feed will be removed after that (Please be advised feeds/podcasts cannot be deleted/unsubscribed during active feed updates, please cancel a feed update or wait until the update is completed to delete feeds)