Hello, new member here.
First, thank you all involved in making this great piece of software, which
I have already experienced without issues during a couple of months.
Back then, it was on Openwrt, in a TP-LINK Archer C-7 router, bandwidth
capped to 60 Mbps (on the device's limits, but still making Internet usage
much smoother to all users).
Then I moved the router to a debian 10 Celeron J1900 mini-ITX, 4 GB of RAM,
two entry level Gigabit cards.
So far I couldn't get the stable A's in dslreports test I was getting with
the previous setup.
The point is that my Internet has been upgraded from 60 Mbps to 240/20
Mbps. SInce most, if not all, devices are still 100 Mbps, I'm currently
capping cake at 85/18.
I basically "transported" the cake settings from Openwrt to debian,
basically adjusting the speed limits.
I would like to know where I start troubleshooting this, to help identify
what is causing bufferbloat on this new setup.

Follow cake settings, then tc, then network hardware info

*CAKE*

# Uplink and Downlink values are in kbps
UPLINK=17500
#DOWNLINK=216000
DOWNLINK=90000

# SQM recipe to use. For more information, see /usr/lib/sqm/*.help
SCRIPT=piece_of_cake.qos

# Optional/advanced config

ENABLED=1
QDISC=cake

#LLAM=tc_stab
LINKLAYER=ethernet
OVERHEAD=22
#STAB_MTU=2047
#STAB_TSIZE=512
#STAB_MPU=0

#ILIMIT=
#ELIMIT=
#ITARGET=
#ETARGET=

# ECN ingress resp. egress. Values are ECN or NOECN.
IECN=ECN
EECN=NOECN

# Extra qdisc options ingress resp. egress
IQDISC_OPTS="nat dual-dsthost"
EQDISC_OPTS="nat dual-srchost ack-filter"

# CoDel target
#TARGET=5ms

#ZERO_DSCP_INGRESS=1
#IGNORE_DSCP_INGRESS=1

*TC SETTINGS:*

qdisc noqueue 0: dev lo root refcnt 2
qdisc pfifo_fast 0: dev enp2s0 root refcnt 2 bands 3 priomap  1 2 2 2 1 2 0
0 1 1 1 1 1 1 1 1
qdisc cake 801b: dev enp3s0 root refcnt 2 bandwidth 17500Kbit besteffort
dual-srchost nat nowash ack-filter split-gso rtt 100.0ms noatm overhead 22
qdisc ingress ffff: dev enp3s0 parent ffff:fff1 ----------------
qdisc cake 801c: dev ifb4enp3s0 root refcnt 2 bandwidth 90Mbit besteffort
dual-dsthost nat wash no-ack-filter split-gso rtt 100.0ms noatm overhead 22

*NETWORK HARDWARE:*

SCSI
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: enp2s0
       version: 06
       serial: c4:e9:84:00:1d:7b
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list
ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd
autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169
duplex=full firmware=rtl_nic/rtl8168e-2.fw ip=192.168.1.1 latency=0
link=yes multicast=yes port=MII speed=1Gbit/s
       resources: irq:17 ioport:e000(size=256) memory:d0704000-d0704fff
memory:d0700000-d0703fff
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: enp3s0
       version: 0c
       serial: 44:8a:5b:94:96:37
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list
ethernet physical tp aui bnc mii fibre 10bt 10bt-fd 100bt 100bt-fd
1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169
duplex=full firmware=rtl8168g-2_0.0.1 02/06/13 ip=179.210.1.62 latency=0
link=yes multicast=yes port=MII speed=1Gbit/s
       resources: irq:18 ioport:d000(size=256) memory:d0604000-d0604fff
memory:d0600000-d0603fff
  *-network:0
       description: Ethernet interface
       physical id: 1
       logical name: ifb4enp3s0
       serial: 76:6b:66:3c:6d:e9
       capabilities: ethernet physical
       configuration: broadcast=yes
  *-network:1 DISABLED
       description: Ethernet interface
       physical id: 2
       logical name: ifb1
       serial: 02:9e:3d:12:6e:16
       capabilities: ethernet physical
       configuration: broadcast=yes
  *-network:2 DISABLED
       description: Ethernet interface
       physical id: 3
       logical name: ifb0
       serial: 32:fe:93:2e:3a:1d
       capabilities: ethernet physical
       configuration: broadcast=yes