Hello,
is it possible to get a new IP address from the pool when releasing the old one on my client?
Everytime i try this, i get the same again 
It is like the RB remembers the client for quite a while and assign the same address to it. Is it possible to clear this table or information?
You can make and scheduler each minute to invoke this script
/ip dhcp-server lease remove [find dynamic]
Any reason for requesting a new one? I have set my DHCP server (home environment) to 1 year 
This way all clients gets same IP all the time and I can easily monitors them in Splunk.
Any client or another mikrotik router as client?
Doing this would run the risk of the DHCP server assigning the same IP to a second device, before the first device has released it.
DHCP server must check if someone have the IP before assign it, no matter if some device has static or dynamic
Short answer: Yes
Long answer: Yes. I want to do something like the ISPs do: Get a new IP address with reconnecting your PPPoE session. In my case with release and renew of the DHCP address
Good idea, but the client gets the same address all over again
I believe there is a correlation between assigned address and the MAC address of the client. It seems that the RB blocks the IP address for some time and if the “old” owner comes around, it gets its old address.
Preferable any client
This does not answer my question. I do not like all getting new ip all the time. I do understand that an ISP do this due to shortage of IP, but this in private IP, I do not understand. You can set up 10.0.0.0/16 and get as may IP as you like.
So why should a client get new IP all the time?
Make it harder for you to track back to a client that has done some wrong?
I share these useful examples
/ ip dhcp-client release 0
/ ip dhcp-client release [find interface =ether1]
It is valid for (release) or (renew)
God bless you