Random/wrong selection of the shop language during the page update issue

I have a shopware shop with two subshops

  1. main shop DE
  2. sub language shop. EN

When I visit default shop (DE) and refresh start page few times, I see EN shop selected in the top shop navigation dropdown which is wrong. If I am in DE shop then only DE should be selected, and this happens sometimes only.

What is the issue here, is it a cache issue, or issue due to some plugin. If its some plugin then why it doesnt happen everytime.

the site is hosted on cluster environment