I personally find the term over-used, but consider [dysfunction][1] or dysfunctional:

abnormal or unhealthy interpersonal behavior or interaction within a group

(link and definition from M-W).

It doesn't fit your example sentence, but a slight tweak gives:

Rampant dysfunction among the coworkers caused the project to be delivered late. [1]: https://www.merriam-webster.com/dictionary/dysfunction

I personally find the term over-used, but consider dysfunction or dysfunctional:

abnormal or unhealthy interpersonal behavior or interaction within a group

(link and definition from M-W).

It doesn't fit your example sentence, but a slight tweak gives:

Rampant dysfunction among the coworkers caused the project to be delivered late.