Replaced hot end and nozzle, z offset seems to be -0.950 and bltouch isnt bed levelling correctly?

General Discussion
1

Basic Information:

Printer Model: Creality CR-10S with BLTouch
MCU / Printerboard: Creality 2.1 Board
Host / SBC: Raspberry Pi 3b (sorry if this is wrong)
klippy.log attached

Describe your issue:

Hi all,
A little new to 3D printing in general and to Klipper, I decided to flash my board with Klipper though and have had numerous great prints to date, I overtightened my nozzle however causing it to snap in the hot end thus needed replacing, I replaced the hot end with a similar model to the stock one as well as the 2 fans either side, the cable running back to the box and the bowden tubing.
Since then I cant get my z offset or bed levelling correct, ive checked to make sure everything is fastened as well as cleaned the machine and bed after a few failed prints (I have mainly been printing the first layer to check if the issue has been resolved).
For some reason my BLTouch is indicating that the 4 corners where the screws under the bed are to move up or down are showing to be flat and level but the bed seems to dip in the middle unlike before, im not sure if this is relevant and its only a very minor dip. My prints always seem to not stick to the bed as the extuder is too high though and no matter how many times I run probe calibrate it never seems to work until I manually adjust the z offset to around -1.00 (-0.950 seems to be the sweet spot).
I thought that perhaps with the new nozzle and hot end that the distance between my bltouch and nozzle is slightly different however in the printer.cfg if I try and change z offset under [BLTouch] it wont allow me to enter a negative number and I am not entirely sure im even adjusting the right part.

Basically probe calibrate and heightmap bed levelling always seem to be off by around -0.950 with new parts and I never had this issue before, ive currently got it printing ok but I have to manually set the z offset to that number as the print starts. My klippy log might be a bit of a mess as I spent several hours last night trying to troubleshoot, im afraid to run probe_calibrate again as through alot of trial and error -0.950 seems to be right but in my last 2 attempts before that the number was between -0.9 and -1.0 before it would print correctly.
Any advice appreciated as I may have overlooked something simple.

2

Sorry to reply to my own thread but incase anyone comes across a similar issue, it just didnt seem to make sense with a minus offset.
A related thread was recommended and after some reading in there of a similar post something wasnt right so I stripped it back, tightened the bolts and repositioned the BLTouch as well as giving the bed a really good clean (it wasnt particularly dirty but perhaps it helped).

The thread - My printer is printing in the air (bltouch issue)

Whatever was wrong seemed to always be reading a huge dip in the middle of the bed and im still unsure why as its a flat glass pane with 4 corner tightening screws to lower or heighten the bed. My bed is showing level under heightmap now (I also flipped it the other way around but I would have thought that would lead it to dip upwards, which it has slightly but far less than the initial downwards dip).