Even if there are TMs added in the project settings under All Language Pairs in SDL Trados Studio , in the Editor view no TM results come from those TMs.

You can see in the screenshot below, right at the bottom, there is a yellow exclamation mark that says "You have setup different translation memories or automated translation providers for certain language pairs". That means that if you click on the specific language pair, in our example English (United States) - Spanish (Mexico) on the left side of that window, there will be a checkbox at the top checked - that checkbox option is "Use different translation providers for this language pair". What that option does basically, it tells Studio to use ONLY the TMs that are added there and NOT the ones under All Language Pairs.

Try unchecking that option under the individual language pair and then test again.
 

That is because under the specific language pair, the option "Use different translation providers for this language pair" is checked. When that option is checked under the specific language pair, no TMs that are added under All Language Pairs will be used for that specific language pair.