Nitrite spike!

My tank has been doing well but I noticed foam beginning along the glass of my aquarium though my water is still crystal clear. So I did an ammonia, nitrite, nitrate and pH tests. (I am still cycling, though till now had not had any problems)
I have 3 axolotls in my tank. I haven't noticed them showing any real changes or stress signs - that may be due to the prime detoxifying the nitrite at least.

My ammonia was below 0.25. It looked closest to 0
Nitrate was between 10 and 20 (they had some hidden poops and food again - had just cleaned the tank 2 days before)
Ph is between 7.2 and 7.6. I plan on doing a High range PH test later tonight to determine a closer reading.

Nitrite however had spiked. It appears to be up at 2 ppm... possibly between 2 and 5!

I`ve been doing 15-25% water changes daily, I use Seachem Prime to treat my water and have been trying to ensure I siphon up all extra food and poops.

I have placed a single ammonia/nitrite remover inside my filter as an emergency action to help lower the levels a bit (seems to be helping, the levels appear to have lowered slightly and there isn't as much foam trying to build up)

Any good suggestions on what else I can do to help lower my nitrite levels and finish my tanks cycling??

Keep on cycling the tank. Do you have a filter? Have a sponge on the filter intake, or a filter with a sponge inside will give the bacteria more media to grow on. Otherwise, keep doing daily water changes and closely watching the parameters

I have the Marineland penguin power filter 350.
I've placed 3 filter inserts (marineland cartridge rite-size C) inside. I had 4 before but I had to remove one to fit in the ammonia/nitrite remover packet.

So far my nitrite has dropped well. It seems to be done to in-between 0.25 and 0.5... Closer to 0.25 (though maybe my hopefulness is making my colour judgement biased)

Ammonia has stayed stable at closest to 0.

My PH is a little high I think though :/ It appears to be around 7.8.