Do not restart an analysis from the end of a load step and then select the Specify option to save the restart points for the following load step. For example, do not restart an analysis from the end of a load step 2 and set the Specify option to Load Step 3.
Here's what document tells about retaining files after full solve:
When restart points are requested, the necessary restart files are always retained for an incomplete solve due to a convergence failure or user request. However, when the solve completes successfully, you have the option to request to either keep the restart points by setting this field to Yes, or to delete them by setting this field to No. You can control this setting here in the Details view of the Analysis Settings object, or under Tools> Options in the Analysis Settings and Solution preferences list. The setting in the Details view overrides the preference setting.
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