There's simply no way to know why certain steps randomly fail without more information. See here on what to provide so we can continue troubleshooting. If you regard that information as sensitive, you can attach it to a support ticket which is confidential, unlike this forum.
I noticed that one of your tests relies heavily on fixed Execution Delays. This typically is a bad practice and we recommend using a fixed delay as a last resort. Instead, use Verifications and Waits to ensure the test is in the correct state before continuing.
If executing via Quick Execute, you can also increase the global Wait on elements timeout setting in Quick Execution Options. The bottom of this page shows where to find that setting. If it's a Test List, you can do the same from the Test List Settings. This will extend the built-in wait for each action step.
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