Ordering of items does not match RSS Feed

#1

Wondering if anyone else has noticed that sometimes posts appear out of order, one of the forums I follow via RSS:

When I look at the RSS for this:

	<channel>
		<title>CityCyclingEdinburgh Forum &#187; Recent Posts</title>
		<link>http://citycyclingedinburgh.info/bbpress/</link>
		<description>CityCyclingEdinburgh Forum &#187; Recent Posts</description>
		<language>en</language>
		<pubDate>Wed, 12 Jun 2019 13:58:02 +0000</pubDate>
		<item>
			<title>Arellcat on "Today&#039;s rubbish cycling"</title>
			<link>http://citycyclingedinburgh.info/bbpress/topic.php?id=7059&amp;page=135#post-308586</link>
			<pubDate>Wed, 12 Jun 2019 14:45:36 +0000</pubDate>
			<dc:creator>Arellcat</dc:creator>
			<guid isPermaLink="false">308586@http://citycyclingedinburgh.info/bbpress/</guid>
			<description>&#60;p&#62;Some context for those who don't follow road cycling:&#60;/p&#62;
&#60;p&#62;&#60;a href=&#34;https://www.bbc.co.uk/sport/cycling/48612884&#34; rel=&#34;nofollow&#34;&#62;https://www.bbc.co.uk/sport/cycling/48612884&#60;/a&#62;
&#60;/p&#62;</description>
		</item>
		<item>
			<title>stiltskin on "Today&#039;s rubbish cycling"</title>
			<link>http://citycyclingedinburgh.info/bbpress/topic.php?id=7059&amp;page=135#post-308585</link>
			<pubDate>Wed, 12 Jun 2019 14:39:47 +0000</pubDate>
			<dc:creator>stiltskin</dc:creator>
			<guid isPermaLink="false">308585@http://citycyclingedinburgh.info/bbpress/</guid>
			<description>&#60;p&#62;Chris Froome
&#60;/p&#62;</description>
		</item>
		<item>
			<title>Arellcat on "Today&#039;s rubbish cycling"</title>
			<link>http://citycyclingedinburgh.info/bbpress/topic.php?id=7059&amp;page=135#post-308584</link>
			<pubDate>Wed, 12 Jun 2019 14:03:15 +0000</pubDate>
			<dc:creator>Arellcat</dc:creator>
			<guid isPermaLink="false">308584@http://citycyclingedinburgh.info/bbpress/</guid>
			<description>&#60;p&#62;This is another incident that more properly belongs in the currently imaginary &#34;Today's rubbish bicycle&#34; thread, that I may yet start.&#60;/p&#62;
&#60;p&#62;Rubbish cycling brought to you by the child who was cycling to school, but who appeared from round the corner of a wall and nearly crashed into me.  &#34;Almost&#34;, because I avoided the crash by application of &#60;code&#62;MAD SKILLZ&#60;/code&#62;.&#60;/p&#62;
&#60;p&#62;Unfortunately said mad skillz resulted in the total collapse of the forks of my lovely sparkly purple recumbent, of which I am hugely fond and about which I am now desperately sad and annoyed, and agog at the eyewatering repair bill that I can really do without right now.
&#60;/p&#62;</description>
		</item>

So these are shown out of order the post at 14:03 is shown last and with a time of 14:54, then is should have been the post at 14:39:47 (Chris Froome) then the post at 14:45:36 (link to bbc article).

So the 14:39 and 14:45 posts are in the correct order, but the 14:03 post is out of order. Any idea’s why?