Are you following Salesforce best practice?
Build in a test environment
For each object, use one automation tool
Have only one record-change process per object
What Mode is your automation running in? (User or System mode)
What triggers your automation to run?
(User clicks button or link, User accesses Lightning page, Community page, Visualforce page, or custom tab, User accesses item in a utility bar, Process starts, or Apex is called, Record is changed, Invoked by another process, Platform event message is received)
Order of Operations
Workflows (no limits)
Process Builder , Flows and Apex (SOQL and DML limits)
Automation Theory (State Machines vs Process Engines )