Menu ends up in top menu spot

This issue only occurs on this page:
https://smallcaps.com.au/announcements/

If you scroll down then back up, the main menu ends up at the top of the page:
https://imgur.com/a/NaWdiKW

Also the sticky menu does not work on this page when the menu is in its normal position…but works when it is also at the top of the page.
Can you please see/fix what is causing this issue?

It doesn’t do it every time but if you reload the page a few times, scroll to the bottom, then scroll back up it occurs and you can see it.

Main menu/sticky menu issue also intermittently occurring on this page:
https://smallcaps.com.au/volume-stocks/

Have tried multiple browsers, all show the same…one of these two things happen:

1) If you scroll down quickly as page loads then scroll back up you get this:
http://tinypic.com/r/2a4s85e/9
Also the menu does not stick to the top of the page when you scroll down.

2) When you scroll down and up the page the main menu is in the correct place, however there is no sticky menu:
http://tinypic.com/r/otj9uh/9

This is the code in this page (https://smallcaps.com.au/announcements/) loading the widget that may be causing the issue:

<script src=”https://cloud.weblink.com.au/styles/chartstyles/responsive/WL_TabFrameFunctions.js”></script&gt;
<script type=’text/javascript’ src=’https://cloud.weblink.com.au/library/js/weblinkframecontroller.js’></script&gt;
<iframe src =”https://cloud.weblink.com.au/Clients/SmallCaps/announcements.aspx&#8221; width=”100%” height=”1200″ frameborder=”0″ scrolling=”no” ALLOWTRANSPARENCY=”true” ></iframe>

This is the code in this page (https://smallcaps.com.au/top-stocks/) loading the widget that may be causing the issue:

<script src=”https://cloud.weblink.com.au/styles/chartstyles/responsive/WL_TabFrameFunctions.js”></script&gt;
<script type=’text/javascript’ src=’https://cloud.weblink.com.au/library/js/weblinkframecontroller.js’></script&gt;
<iframe id=’wl-top-report’ src =”https://cloud.weblink.com.au/Clients/SmallCaps/winnerslosersreport.aspx&#8221; width=”100%” height=”740″ frameborder=”0″ scrolling=”no” ALLOWTRANSPARENCY=”true” ></iframe>

http://tinypic.com/r/zskbur/9

Thanks Catalin, I’ve determined that it’s the javascript code I pasted in the previous message (not a plugin).

However have no idea how it is effecting it or what I need to change so that it doesn’t mess up the menu?

For the video you sent me the javascript in that page (https://smallcaps.com.au/announcements/) operating is:
<script src=”https://cloud.weblink.com.au/styles/chartstyles/responsive/WL_TabFrameFunctions.js”></script>
<script type=’text/javascript’ src=’https://cloud.weblink.com.au/library/js/weblinkframecontroller.js’></script>
<iframe src =”https://cloud.weblink.com.au/Clients/SmallCaps/announcements.aspx” width=”100%” height=”1200″ frameborder=”0″ scrolling=”no” ALLOWTRANSPARENCY=”true” ></iframe>

My question is what part of it and why is causing the issue? How can I fix it?
http://tinypic.com/r/v6ofpd/9