strange, so I guess the only thing I could do is to to ask my university whether it's possible to update the lime survey version.
I highly recommend that. The very first releases of a new branch generally still have one or the other problem. The LS 3.x release was "relatively" good in this regard, at least compared to LS 2.7x and LS 4.x. But still, in the first view weeks/months of a new major branch of LS there are many updates fixing bugs and security issues.
And: Just like any other software, Limesurvey should be updated on a regular basis. LS 3.0.0 was released in January 2018. That means your installation has not received any security updates or bug fixes for 2,5 years.
I don't think that this is acceptable for a software that is potentially used to collect sensitive data from respondents.
However, when you talk to them, make it clear that they should NOT update to LS 4.x just yet, because then they just move from a very early version of LS 3.x to an early version of LS 4.x that still has quite a few bugs that need to be fixed.
Stay with LS 3.x for now, but update to the latest version.