This is a known issue within Jira and affects issues with a long history ( it is estimated that the problem starts by ca. 100 entries in the History tab of the issue. The issues in the Atlassian Support system are: JRASERVER-45903 and JRACLOUD-45903. In case your instance is affected by this problem, we recommend that you create a new issue (for example, create issues for vacation planning on a yearly basis: Vacations | 
