Update: I opened up the casing of my Lelit MaraX and discovered there was air in several lines, the most important being most likely one that takes water to the grouphead and perhaps also works as part of the thermosyphon. After fiddling (emptied boiler through drain valve twice, tried priming pump with a squeeze bottle etc., and nothing seemed to work.)

Main symptoms of air pocket in line for me were grouphead dispensing out very little water if any, mostly coming out as steam, and shot pulling was impossible, because the pump would never (even) with a blind filter, go above 2 bar. Also I noticed the thermosyphon cycles not being more than a little twitch of the pressure needle, instead of going very briefly to even 9 bars. So there are some things to look out for.

Now that the pump is working normally in dispensing water through group your normal brew lever raise should give you about
2-3 bars.

[*]Here was the solution for the problem found on Reddit;[*]

This works to get the water pump primed by basically forcing water through the pump. While the machine is cold: - If you have or can obtain a small baster (a turkey baster would be too big) or a large ear syringe (basically, anything that squirts through a nozzle) that the water hose from the reservoir can fit over, you can pump water into the machine to prime it. - Fill the syringe with water and attach to intake hose in the tank by pushing the nozzle into the hose. You may have to remove a particle filter if attached.
- Open the Steam Valve by turning knob into full open (this is to let air escape) and place a cup under the steam wand. - Activate the Power and Coffee switches and squeeze the syringe to push water through the tube. If you need to refill the syringe with water, pinch the hose, remove the syringe and add the water. Reattach to the hose. - Once you see water exiting the syringe through the hose for 3-5 seconds, power down the espresso machine immediately to remove probability of another air pocket. - Remove syringe from intake hose (replace particle filter if removed previously) and insert intake hose into the filled water tank/reservoir. - Power the espresso machine back on and allow water to come through steam wand. After water appears in the cup, power off the machine. - The pump should be primed.

New to the forum, so bear with me.
I purchased the Lelit MaraX in November of 2020. Everything has been working great until a couple days ago.

Problem is low pump pressure/ pump not giving water properly to the group.
Background;

Ordered the bigger water softener and decided to do a quick descale before changing in a new water softener. During the descale the mara X pump was working fine. After having done descaling I changed the water softener into the 70l bigger one from standard 35l. After changing the water softener the pump would not get a lot of pressure (for example with blind filter it would be a struggle to get to 2 bars).

And also would be putting out very little water and lots of steam from the grouphead.
As I was trying to get water from the grouphead and also the pump to pull water through filter I would run it for a minute or so.
At this point the pump would start 'refilling' for an extended time, and only was able to draw a very small amount from the reservoir.

Water tap and steam wand are seemingly working without problems.

Would you reckon the pump is up for replacement or could this be caused by an air bubble somewhere in the line?

I will investigate further today when I get back home

Greetings,
Stenkka

did you tried without the water softener in the tank?

Sounds like the filter wasn't completely filled and flushed when you put it in. You should be able to take the filter out, forcibly prime the pump if it doesn't prime by itself with no filter, then flush the filter some more and reinstall it. If the pump recovers, it may be okay for a while.
If the pump is still weak or completely fails to prime, replace the pump.

Opened the side covers to expose internals, there is atleast one line that has air in it, will see if I can get that sorted, incase that would be causing issues.