Docker is not loading Node image from cache - node.js

Question

I'm using docker-compose in my local environment for development. I have 4 docker containers, 3 of them based on docker-node.
When I run docker-compose up --build, I see most of the building steps are loaded from cache, so they usually run really fast. But since a couple of days ago, I noticed they began to take a very long time to build (around 10 minutes in total), even if nothing had changed.
I also noticed that all the building steps seem to be loaded from cache, except for the first one: FROM node:8. And indeed, it always takes the longest to print the first step. Here's the complete output:
Building mongo-seed
Step 1/10 : FROM node:8
---> d575940ea42b
Step 2/10 : ENV NODE_ENV=development
---> Using cache
---> 64584d7c28d1
Step 3/10 : WORKDIR /seeder
---> Using cache
---> 2481554b20cc
Step 4/10 : COPY ./server/app/models ./app/models
---> Using cache
---> ad6c76419ffd
Step 5/10 : COPY ./server/config ./config
---> Using cache
---> 379dd9e19e67
Step 6/10 : COPY ./server/util ./util
---> Using cache
---> 1e6db5498a1a
Step 7/10 : COPY ./server/seed ./seed
---> Using cache
---> 659f531ef78d
Step 8/10 : COPY ./server/package.json ./package.json
---> Using cache
---> 4eb54f2548b9
Step 9/10 : RUN npm i mongoose
---> Using cache
---> c34967921c69
Step 10/10 : CMD npm run seed
---> Using cache
---> 0274c6635c1d
Successfully built 0274c6635c1d
Successfully tagged javorosas_mongo-seed:latest
Building server
^[Step 1/17 : FROM node:8
---> d575940ea42b
Step 2/17 : RUN apt-get update
---> Using cache
---> 4cb3797b4737
Step 3/17 : RUN apt-get install -y graphicsmagick
---> Using cache
---> a33dcf53e585
Step 4/17 : RUN npm i -g webpack node-gyp nodemon
---> Using cache
---> c961ca565c54
Step 5/17 : ENV NODE_ENV=development
---> Using cache
---> c63d1a245873
Step 6/17 : WORKDIR /server
---> Using cache
---> 7ac6181902ca
Step 7/17 : COPY ./server/package.json .
---> Using cache
---> ebba732f0210
Step 8/17 : COPY ./common ../common
---> Using cache
---> 47a9e631cc57
Step 9/17 : RUN npm install --quiet && npm cache clean -f
---> Using cache
---> 8d57a963d1ac
Step 10/17 : COPY ./server/constants ./constants
---> Using cache
---> a6a8884a1343
Step 11/17 : COPY ./server/util ./util
---> Using cache
---> dfd9de1db59e
Step 12/17 : COPY ./server/webpack.ssr.js .
---> Using cache
---> 547282293bc6
Step 13/17 : COPY ./server/src ./src
---> Using cache
---> e7821c59d012
Step 14/17 : RUN npm run build
---> Using cache
---> 184527650563
Step 15/17 : COPY . .
---> 8be425af57c7
Step 16/17 : EXPOSE 2018
---> Running in c662570856a5
Removing intermediate container c662570856a5
---> 1eb434d7e0ea
Step 17/17 : CMD npm run start:dev
---> Running in 613c7064436e
Removing intermediate container 613c7064436e
---> f37d511ffc78
Successfully built f37d511ffc78
Successfully tagged javorosas_server:latest
Building client
Step 1/10 : FROM node:8
---> d575940ea42b
Step 2/10 : RUN npm i -g webpack
---> Using cache
---> b8428ab7c232
Step 3/10 : ENV NODE_ENV=development
---> Using cache
---> bbfbbb480a46
Step 4/10 : WORKDIR /client
---> Using cache
---> 2203bdaa2cea
Step 5/10 : COPY ./client/package.json .
---> Using cache
---> fe5ead356992
Step 6/10 : COPY ./common ../common
---> Using cache
---> db9c274937cc
Step 7/10 : RUN npm install --quiet && npm cache clean -f
---> Using cache
---> 16be06b426b3
Step 8/10 : COPY . .
---> c96343b67244
Step 9/10 : EXPOSE 2017
---> Running in 7460e5f1d0c6
Removing intermediate container 7460e5f1d0c6
---> 8436f916f585
Step 10/10 : CMD npm run start
---> Running in fbcf8af08cbf
Removing intermediate container fbcf8af08cbf
---> 47958626245f
Successfully built 47958626245f
Successfully tagged javorosas_client:latest
javorosas_mongo_1 is up-to-date
Starting javorosas_mongo-seed_1 ... done
Recreating javorosas_server_1 ... done
Recreating javorosas_client_1 ... done
Attaching to javorosas_mongo_1, javorosas_mongo-seed_1,
javorosas_server_1, javorosas_client_1
Any ideas on why it could have started to slow down?