Image posts picture doubling in RSS

Was working perfect till upgrade to WP 4.7
The problem is: two identical pictures in a row in the RSS if the post already has it inside it’s content.

Well, I meah that in text or gallery or video post everything is ok: in RSS I have only the thumbnail inserted by this nice plugin.

But in picture posts when the whole post consists of one image + short description, and the thumbnail is the same as the post image, I have in RSS two same images in a row + that short description ??

Clever feed burners like Feedly or Opera anyway shows everything right. But old and ugly (like livejournal.com’s importer) shows both images now ??

BT, I am not sure that this is a problem of combination of 2 monthes old SB RSS + new WP 4.7, maybe it’s just a coincidence. But I am worried about this debug information in settings, is it normal?

Debug – hooks & filters

Warning: ksort() expects parameter 1 to be array, object given in /wp-content/plugins/sb-rss-feed-plus/SB-RSS_feed-plus.php on line 415
>>>>> rss_item
5 (object) SB_RSS_feed_plus -> feed_addMeta (1)
10 jetpack_enhanced_distribution_post_id (1)

Warning: ksort() expects parameter 1 to be array, object given in /wp-content/plugins/sb-rss-feed-plus/SB-RSS_feed-plus.php on line 415
>>>>> rss2_item
5 (object) SB_RSS_feed_plus -> feed_addMeta (1)
10 jetpack_enhanced_distribution_post_id (1)

Warning: ksort() expects parameter 1 to be array, object given in /wp-content/plugins/sb-rss-feed-plus/SB-RSS_feed-plus.php on line 415
>>>>> the_excerpt_rss
8 ent2ncr (1)
10 convert_chars (1)
(object) SB_RSS_feed_plus -> feed_update_content (1)
1000 st_feed_post_format (1)

Warning: ksort() expects parameter 1 to be array, object given in /wp-content/plugins/sb-rss-feed-plus/SB-RSS_feed-plus.php on line 415
>>>>> the_content_feed
10 wp_staticize_emoji (1)
_oembed_filter_feed_content (1)
(object) SB_RSS_feed_plus -> feed_update_content (1)
1000 st_feed_post_format (1)

PS: My RSS feed is https://vorchuchelo.com/feed/