Hi, I tried posting a link while using the site on a tablet and it refused to paste the link at the end of the post, but within or before a quote that was in the post. Very odd. Edit It was this post if that makes any difference. The UK Toy Discussion
OK, I tested the Samsung Browser, aka "Internet" on my Android 6.x. Similar issues are present. At bottom, the "paste" dialog will pop up when putting cursor in empty space. If you attempt to long press or otherwise get the paste dialog up in the middle of text blocks, it won't trigger (easily). I did get the paste box to open after putting the cursor in it's desired place, between text, and then lightly tapping again in the same spot. It's not perfect and easily f'd up, but it is possible. Will see if there is anything I can do.
PS - You should really install Chrome for Android. Made by Google, works great. Not saying that's a fix, but it's better IMO for multiple reasons.