Mobile Safari iOS 9.3 makes multiple HTTP requests, finally showing error

A website which used to work does no longer after the iOS 9.3 update. We get the following error in mobile Safari:

A problem occurred with this webpage so it was reloaded

and

A problem repeatedly occured on "http://domain.ch/en/search/rent/f/"

At first we thought there was an endless redirect going on. But that is not the case.

• The site works in all other browsers, it works with iOS 9.2 (no changes to the code were made)
• iOS Safari sends multiple requests, even though the first one was already successfully returned (HTTP Status 200)

This is the access log:

127.0.0.1 - - [24/Mar/2016:12:08:30 +0100] "GET /en/search/rent/f/ HTTP/1.1" 200 5028 "-" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:31 +0100] "GET /wp-content/themes/theme/assets/js/scripts.100.js HTTP/1.1" 200 121450 "http://lo.domain.ch/en/search/rent/f/" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:31 +0100] "GET /en/search/rent/f/ HTTP/1.1" 200 5028 "-" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:32 +0100] "GET /wp-content/themes/theme/assets/js/scripts.100.js HTTP/1.1" 200 121450 "http://lo.domain.ch/en/search/rent/f/" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:32 +0100] "GET /en/search/rent/f/ HTTP/1.1" 200 5028 "-" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:32 +0100] "GET /wp-content/themes/theme/assets/js/scripts.100.js HTTP/1.1" 200 121450 "http://lo.domain.ch/en/search/rent/f/" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:33 +0100] "GET /en/search/rent/f/ HTTP/1.1" 200 5028 "-" "Mozilla/5.0 (iPhone; CPU   iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"
127.0.0.1 - - [24/Mar/2016:12:08:33 +0100] "GET /wp-content/themes/theme/assets/js/scripts.100.js HTTP/1.1" 200 121450 "http://lo.domain.ch/en/search/rent/f/" "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13E230 Safari/601.1"

I currently don't know what the cause of this could be.

I'm posting this in the hope that anybody else has encountered something similar since the iOS 9.3 update and has some insight into this strange behaviour.