Help! My FG is always too high. What am I doing wrong?

[Wolfhaus]

Been brewing about 2 years so I am not nearly an expert. I batch sparge and follow my process, temperatures, and document everything throughout. My OG is always on the mark or very close. I use a stir plate to make a good starter. When I put the fermenter into my refrigerator at 63? I get a great reaction within 12- 18 hours. I usually let it sit for a couple weeks before going to secondary. I will let it sit in there sometimes a few weeks. Then into cold crash for at least 10 days. Does it matter how long I let it sit in the primary? Or the secondary? Or it is something with the process? The beer isn't bad to drink - it's always "sweet". I usually end up between 4-5% abv. It seems to me the yeast is not breaking down the sugars. I have changed the water. I have changed from fly sparge to batch - still high FG I'm lucky to get it to 1.013 on any type I brew. Generally I do Alt's, Ale's, Stout's. Any advice is appreciated.

[Oginme]

Can you give a few specific examples citing your mash temperature, OG, FG, yeast strain and from the session' tab, the measured attentuation.

My first reaction is that your actual mash temperature is higher than your thermometer indicates, but enough examples may confirm or reveal a different issue.