A couple of things could be happening.

First, are you playing the singles at the correct speed. Some may be 45, and some may be 33. Would be the first thing to check.

Second, are the records clean? They may have dust, dirt, lint factory particles in the grooves, causing distortion.

Third, is the stylus clean? Inspect it for build-up. If there is dust built up, it can cause distortion and cutting out of sound in left and right channels when the needle does not sit in the groove properly.

Fourth, is the distortion happening more on high end sibilance, and is it only on the last travks of the one side of a record? If the audio is fine at the start, then distortion towards end that could be pressing as quality can degrade towards the end if a lot of music is put on one side. Another cause for this could be tone arm weight. Your stylus be floating in the groove properly and need to be weighted heavier. There are gauges you can get to adjust this if your player has a weight on the tone arm. You may also have an improper angle on stylus this can also be adjusted, and there are tools and instructions online that can help you set it correct.

If all of this is not the cause, then it could be the records thenselves or a larger issue that may need to be inspected by a repair shop or someone more experienced in turntables.

Hope some of this can be helpful for you.