Site won't load unless I remove site's cookies

Question

I have a problem with loading one site (removed the name in order not to advertise) from my PC. Actually this problem appeared with several different sites. 'Help centers' of those sites usually reply something like 'we can not reproduce the issue'.

Use case:

1. Load the site first time (loaded correctly).
2. Load the site second time (reload). Site won't load, empty page with 'No data received' after timeout.
3. Remove cookies for the site, now can repeat p.1.

OS Ubuntu 15.10, tried Google Chrome (v.48.0.2564.109, 64-bit) and Mozilla Firefox (v.44.0.2).

My question: is there any ways to find out the cause? Tried to search, but all the solutions were related to specific browsers and were fixed after update.

What I also tried to do:

• rebooted router
• brought my laptop to another network (from home to work) and it worked correctly right away.
• reinstalled Ubuntu on my laptop, still have the same problem
• tried on another laptop (with Ubuntu) but with the same home-network, still have the same problem
• tried to open this site on Android tablet - worked OK
• technician from internet provider came and checked router and internet connection, all OK, but issue is still reproducible
• router factory reset (push back side button for 30s) did not help

Could that be a problem with my network or internet provider?

Answer 1

The problem was due to a unfavorable automatically choosen MTU mtu discovery, that lead to fragmentation. As the page did not allow fragmentation the connection failed (ICMP can't fragment - type 3, code 4). After decreasing the MTU form 1500 to 1440 all problems were gone.

On Linux:

ip link set dev <dev> mtu 1400

or

ifconfig <dev> mtu 1400

On Windows:

netsh interface ipv4 show interfaces
netsh interface ipv4 set subinterface <devIDX>  mtu=1440 store=persistent